Pop/Species Growth Ratio Formula - It needs adjusting, badly.

  • We have updated our Community Code of Conduct. Please read through the new rules for the forum that are an integral part of Paradox Interactive’s User Agreement.

vladimirovalenina

Recruit
82 Badges
Jun 8, 2016
6
0
  • Cities in Motion 2
  • Cities: Skylines - After Dark
  • Europa Universalis IV: Cossacks
  • Cities: Skylines - Snowfall
  • Stellaris
  • Stellaris: Digital Anniversary Edition
  • Europa Universalis IV: Common Sense
  • Crusader Kings II: Horse Lords
  • Europa Universalis IV: Mare Nostrum
  • Hearts of Iron IV: Cadet
  • Europa Universalis IV: Rights of Man
  • Tyranny: Archon Edition
  • Magicka: Wizard Wars Founder Wizard
  • Stellaris: Leviathans Story Pack
  • Cities: Skylines - Natural Disasters
  • Hearts of Iron IV: Together for Victory
  • Steel Division: Normandy 44
  • Cities: Skylines - Mass Transit
  • Europa Universalis IV: Mandate of Heaven
  • BATTLETECH
  • Surviving Mars
  • Hearts of Iron IV: Death or Dishonor
  • Stellaris: Humanoids Species Pack
  • Cities: Skylines - Green Cities
  • Surviving Mars: First Colony Edition
  • Crusader Kings III: Royal Edition
  • Crusader Kings III
  • Hearts of Iron IV: Expansion Pass
  • Stellaris: Federations
  • BATTLETECH: Heavy Metal
  • Stellaris: Lithoids
  • Age of Wonders: Planetfall Season pass
  • Age of Wonders: Planetfall
  • BATTLETECH: Season pass
  • Cities: Skylines - Campus
  • Europa Universalis IV: El Dorado
  • BATTLETECH: Flashpoint
  • Surviving Mars: First Colony Edition
  • Stellaris: Distant Stars
  • Cities: Skylines - Parklife
  • Cities: Skylines - Parklife Pre-Order
  • Europa Universalis III Complete
  • Steel Division: Normandy 44 -  Back to Hell
  • Europa Universalis III Complete
  • Stellaris: Apocalypse
  • Stellaris: Necroids
  • Victoria 2
  • Cities: Skylines
  • Stellaris - Path to Destruction bundle
  • Europa Universalis IV: Third Rome
The most obvious solution to balance it in a satisfying way would be to restore simultaneous growth, and provide a randomized temporary bonus to immigrant/refugee growth. That way you can get a rapid growth of alien pops but it won't happen every time and it won't stop other pops from growing. To balance mutiple pop species with single pop species, we'll want to provide bonuses to pops based on population size on a given planet, which will provide population growth to a single species planet that would be approximately the same (without bonuses) as a multiple species planet with the same population
 

EvilTom

Lt. General
57 Badges
Dec 15, 2014
1.271
512
  • Crusader Kings II: Charlemagne
  • Stellaris: Synthetic Dawn
  • Stellaris - Path to Destruction bundle
  • Crusader Kings II: Reapers Due
  • Stellaris: Galaxy Edition
  • Stellaris
  • Europa Universalis IV: Mare Nostrum
  • Cities: Skylines - Snowfall
  • Europa Universalis IV: Cossacks
  • Cities: Skylines - After Dark
  • Cities: Skylines Deluxe Edition
  • Sword of the Stars
  • Europa Universalis IV: Res Publica
  • Europa Universalis IV: Wealth of Nations
  • Crusader Kings II
  • Crusader Kings II: Legacy of Rome
  • Crusader Kings II: The Old Gods
  • Crusader Kings II: Rajas of India
  • Crusader Kings II: The Republic
  • Crusader Kings II: Sons of Abraham
  • Crusader Kings II: Sunset Invasion
  • Crusader Kings II: Sword of Islam
  • Europa Universalis IV: Art of War
  • Europa Universalis IV: Call to arms event
  • Europa Universalis IV: Conquest of Paradise
  • Crusader Kings II: Monks and Mystics
  • Stellaris: Megacorp
  • Cities: Skylines Industries
  • Crusader Kings II: Holy Fury
  • Stellaris: Distant Stars
  • Cities: Skylines - Parklife
  • Cities: Skylines - Parklife Pre-Order
  • Stellaris: Apocalypse
  • Stellaris: Humanoids Species Pack
  • Crusader Kings II: Jade Dragon
  • Cities: Skylines - Green Cities
  • Crusader Kings III
  • Cities: Skylines - Mass Transit
  • Europa Universalis IV
  • Cities: Skylines - Natural Disasters
  • Stellaris: Leviathans Story Pack
  • Stellaris: Digital Anniversary Edition
  • Cities: Skylines
  • Hearts of Iron IV: Colonel
  • Hearts of Iron IV: Cadet
  • Stellaris: Galaxy Edition
  • Europa Universalis IV: El Dorado
  • Crusader Kings II: Way of Life
  • Europa Universalis IV: Common Sense
  • Crusader Kings II: Conclave
The most obvious solution to balance it in a satisfying way would be to restore simultaneous growth, and provide a randomized temporary bonus to immigrant/refugee growth. That way you can get a rapid growth of alien pops but it won't happen every time and it won't stop other pops from growing. To balance mutiple pop species with single pop species, we'll want to provide bonuses to pops based on population size on a given planet, which will provide population growth to a single species planet that would be approximately the same (without bonuses) as a multiple species planet with the same population

I do like this, but I had a logical problem.

If you slow down growth on a 10 species planet, doesn't that mean you'll get no POPs appear for longer, but then you'll have several appear at once? This would lead to some weird issues. Would you prefer gluts of population increases over longer periods, or a steady growth? How would we get around that?

I think it's actually, at least logical, for multiple (non-interbreeding) species on a world to cause population growth to be increased. The only things will be competition for space, jobs, amenities, food etc which will encourage or discourage species to migrate or breed.
However... one way of actually countering this is to just have multiple species growing at the same time and scale UP population growth based on population. If each breeding pair always produces >2 children, then it's inevitable for the population to grow more and more as the population grows. There are other impacts, like ethics, morals, laws and policies, education, cost, equality, etc. Also over or covert population controls could be enforced.

Having accelerating population growth would cause issue with unemployment, resource consumption etc, but it will mean that being as population is the new meta, other issues would occur and probably mean snowballing happens more (I personally have little problem with snowballing, but I can understand it makes it less fun for a balanced game).

I want the challenge of overcrowding, joblessness and resource issues caused by robots and too many people. That is a real sci-fi trope and challenge of the future!
 

Arutar

First Lieutenant
47 Badges
May 10, 2017
265
116
  • Stellaris: Synthetic Dawn
  • Stellaris: Humanoids Species Pack
  • Stellaris: Digital Anniversary Edition
  • Stellaris: Leviathans Story Pack
  • Hearts of Iron IV: Together for Victory
  • Europa Universalis IV
  • Europa Universalis IV: Mandate of Heaven
  • Hearts of Iron IV: Death or Dishonor
  • Age of Wonders III
  • Hearts of Iron IV: Expansion Pass
  • Europa Universalis IV: Rights of Man
  • Stellaris: Apocalypse
  • Hearts of Iron IV: Expansion Pass
  • Stellaris: Distant Stars
  • Shadowrun: Dragonfall
  • Stellaris: Megacorp
  • Stellaris: Ancient Relics
  • Age of Wonders: Planetfall
  • Stellaris: Lithoids
  • Europa Universalis IV: El Dorado
  • Hearts of Iron IV: No Step Back
  • Stellaris: Nemesis
  • Stellaris: Necroids
  • Europa Universalis 4: Emperor
  • Crusader Kings III
  • Victoria 2
  • Stellaris: Federations
  • Hearts of Iron IV: La Resistance
  • Europa Universalis IV: Common Sense
  • Europa Universalis IV: Cossacks
  • Europa Universalis IV: Mare Nostrum
  • Stellaris
  • Stellaris: Galaxy Edition
  • Age of Wonders: Planetfall - Revelations
  • Stellaris: Galaxy Edition
  • Hearts of Iron IV: Cadet
  • Hearts of Iron IV: Colonel
  • Hearts of Iron IV: Expansion Pass
  • Stellaris - Path to Destruction bundle
  • Europa Universalis IV: Art of War
  • Europa Universalis IV: Conquest of Paradise
  • Europa Universalis IV: Wealth of Nations
  • Europa Universalis IV: Res Publica
  • Victoria: Revolutions
  • Victoria 2: A House Divided
  • Victoria 2: Heart of Darkness
  • Stellaris: Galaxy Edition
Egalitarians can do it, I'm pretty sure (unless a save from 2.2.1 works differently in the beta). You're right about Xenophiles tho.

Yeah they "can do it", it just incurs a small 20% happiness penalty for the egalitarian faction.

I mean, who needs happiness or influence. It is a small price to pay to manually counter mind numbingly nonsensical (and easy to fix) game design planet by planet, right?
 

Archael90

Field Marshal
18 Badges
Nov 30, 2017
3.160
3.273
  • Stellaris: Humanoids Species Pack
  • Stellaris: Nemesis
  • Stellaris: Necroids
  • Stellaris: Federations
  • Stellaris: Lithoids
  • Stellaris: Ancient Relics
  • Stellaris: Megacorp
  • Stellaris: Distant Stars
  • Stellaris: Apocalypse
  • Surviving Mars
  • Stellaris - Path to Destruction bundle
  • Stellaris: Leviathans Story Pack
  • Stellaris: Digital Anniversary Edition
  • Stellaris: Galaxy Edition
  • Stellaris
  • Majesty 2
  • Stellaris: Synthetic Dawn
  • Stellaris: Galaxy Edition
I think that somewhere (policy, species rights) should be something that allow us to set approximate proportions of empire species, like you now - different main species, citizens, residents, and others, except fanatical xenophiles, of course.
 

Seedy

Sergeant
39 Badges
Mar 1, 2018
72
21
  • Stellaris: Humanoids Species Pack
  • Stellaris: Digital Anniversary Edition
  • Europa Universalis IV
  • Hearts of Iron IV: Together for Victory
  • Europa Universalis IV: Mandate of Heaven
  • Hearts of Iron IV: Death or Dishonor
  • Age of Wonders III
  • Europa Universalis IV: Cradle of Civilization
  • Hearts of Iron IV: Expansion Pass
  • Stellaris: Leviathans Story Pack
  • Stellaris: Apocalypse
  • Europa Universalis IV: Rule Britannia
  • Stellaris: Distant Stars
  • Europa Universalis IV: Dharma
  • Stellaris: Ancient Relics
  • Stellaris: Lithoids
  • Stellaris: Federations
  • Stellaris: Necroids
  • Hearts of Iron IV: Colonel
  • Warlock: Master of the Arcane
  • Europa Universalis IV: El Dorado
  • Europa Universalis IV: Pre-order
  • Europa Universalis IV: Common Sense
  • Europa Universalis IV: Cossacks
  • Europa Universalis IV: Mare Nostrum
  • Stellaris
  • Hearts of Iron IV: Cadet
  • Europa Universalis IV: Rights of Man
  • Stellaris: Synthetic Dawn
  • Europa Universalis IV: Third Rome
  • Stellaris - Path to Destruction bundle
  • Sword of the Stars II
  • Sword of the Stars
  • Europa Universalis IV: Res Publica
  • Stellaris: Megacorp
  • Europa Universalis IV: Call to arms event
  • Europa Universalis IV: Wealth of Nations
  • Europa Universalis IV: Conquest of Paradise
  • Europa Universalis IV: Art of War
One of the annoying things is that they appear to already have [and have had] a habitability filter in place for migration treaties. If I have an alpine race, on alpine worlds, have a migration treaty with some desert races, I get zero pops from them over decades. The instant I get one as a refuge they grow everywhere. This has always been a problem, the migration treaty restricts folks by habitability, but once you have them, in the current or old systems, the pops move to anyplace without regard to habitability, and then get unhappy they moved to Antarctica and its not all bright sunny beaches. :(
 

Shadowstrike

Terrestrial Liability #168
147 Badges
Mar 17, 2001
2.483
1.651
  • Cities: Skylines - Snowfall
  • Europa Universalis IV: Art of War
  • Europa Universalis IV: Conquest of Paradise
  • Europa Universalis IV: Wealth of Nations
  • Europa Universalis IV: Call to arms event
  • For the Motherland
  • Hearts of Iron III
  • Hearts of Iron III Collection
  • Stellaris: Galaxy Edition
  • Hearts of Iron III: Their Finest Hour
  • Europa Universalis IV: Res Publica
  • Victoria: Revolutions
  • Semper Fi
  • Cities: Skylines - After Dark
  • Victoria 2: A House Divided
  • Victoria 2: Heart of Darkness
  • Cities: Skylines Deluxe Edition
  • Crusader Kings II
  • Europa Universalis III
  • Europa Universalis IV: Third Rome
  • Crusader Kings II: Sword of Islam
  • Crusader Kings II: Sunset Invasion
  • Crusader Kings II: Sons of Abraham
  • Crusader Kings II: Legacy of Rome
  • Crusader Kings II: The Republic
  • Crusader Kings II: The Old Gods
  • Crusader Kings II: Rajas of India
  • Victoria 2
  • Sengoku
  • Ship Simulator Extremes
  • Sword of the Stars
  • Sword of the Stars II
  • Supreme Ruler 2020
  • Cities in Motion 2
  • Ancient Space
  • Cities in Motion
  • Arsenal of Democracy
  • Rome: Vae Victis
  • Europa Universalis IV
  • Rome Gold
  • Crusader Kings II: Charlemagne
  • March of the Eagles
  • Majesty 2
  • Magicka
  • Knights of Pen and Paper +1 Edition
  • King Arthur II
  • Impire
  • Heir to the Throne
  • Hearts of Iron IV: No Step Back
  • For The Glory
I do like this, but I had a logical problem.

If you slow down growth on a 10 species planet, doesn't that mean you'll get no POPs appear for longer, but then you'll have several appear at once? This would lead to some weird issues. Would you prefer gluts of population increases over longer periods, or a steady growth?

Theres an easy answer to this. Every time the total "growing" pops add up to a full pop, create a pop from whichever species is furthest along to a full pop, and subtract 1 from the growth counter (which leaves it negative temporarily).

So if you have 0.6 growing humans and 0.3 growing blorgs (this is growth progress), and both grow by a rate of 0.1 each month, the next month, you would generate a human pop and get growth progress of -0.3 humans and 0.4 blorgs (instead of going to 0.7 humans and 0.4 blorgs).
 

Avil

Lt. General
63 Badges
May 20, 2016
1.308
412
  • Europa Universalis IV: Pre-order
  • Cities: Skylines - After Dark
  • Europa Universalis IV: Cossacks
  • Europa Universalis IV: Mare Nostrum
  • Stellaris
  • Stellaris - Path to Destruction bundle
  • Crusader Kings II: Reapers Due
  • Europa Universalis IV: Rights of Man
  • Tyranny: Archon Edition
  • Tyranny: Archon Edition
  • Tyranny: Gold Edition
  • Stellaris: Digital Anniversary Edition
  • Stellaris: Leviathans Story Pack
  • Crusader Kings II: Monks and Mystics
  • Crusader Kings II: Conclave
  • Europa Universalis IV: Mandate of Heaven
  • Shadowrun Returns
  • Surviving Mars
  • Tyranny - Tales from the Tiers
  • Tyranny - Bastards Wound
  • Age of Wonders III
  • Europa Universalis IV: Cradle of Civilization
  • Shadowrun: Dragonfall
  • Stellaris: Humanoids Species Pack
  • Stellaris: Apocalypse
  • Europa Universalis IV: Rule Britannia
  • Stellaris: Distant Stars
  • Prison Architect
  • Stellaris: Necroids
  • Crusader Kings III
  • Stellaris: Federations
  • Stellaris: Megacorp
  • Europa Universalis IV
  • Crusader Kings II: Holy Fury
  • Stellaris: Ancient Relics
  • Stellaris: Lithoids
  • Cities: Skylines
  • Europa Universalis IV: El Dorado
  • Crusader Kings II: Way of Life
  • Europa Universalis IV: Dharma
  • Europa Universalis IV: Common Sense
  • Crusader Kings II: Horse Lords
  • Shadowrun: Hong Kong
  • Stellaris: Synthetic Dawn
  • Europa Universalis IV: Res Publica
  • Magicka
  • Crusader Kings II
  • Crusader Kings II: Charlemagne
  • Crusader Kings II: Legacy of Rome
  • Crusader Kings II: The Old Gods
Technically they don't get unhappy, they just start eating more donuts and buying more washing machines.
Well, to be fair there, more consumed good DOES mean better survivability in rough environment (consumables isn't only washing machines, but also more expensive and more suitable clothes, tools, machinery). Food is another thing, though, not sure why they would eat more. I guess, they binging on it to keep the good spirits at cold nights :p I kinda like that they don't lose mood from bad habitability, but pops still should prefer better suited climate and migrate on given opportunity.

Happiness shouldn't have a major impact on productivity anyway, happiness should provoke events, like strike actions, protestations, sabotages, but not really just reduce productivity to zero due to having a bad mood.
 

FleetingRain

Field Marshal
58 Badges
Aug 2, 2014
3.078
5.912
  • Europa Universalis IV
  • Surviving Mars
  • Stellaris: Federations
  • Crusader Kings III
  • Crusader Kings II
  • Stellaris
  • Pillars of Eternity
  • Imperator: Rome Sign Up
Yeah they "can do it", it just incurs a small 20% happiness penalty for the egalitarian faction.

I mean, who needs happiness or influence. It is a small price to pay to manually counter mind numbingly nonsensical (and easy to fix) game design planet by planet, right?

I never said I like the current system, I just pointed out a possibility OP didn't mention even if it has its own problems (such as not being obvious at first sight, it took me still last Saturday to discover it).
 

Duuk

Reformed Badboy
23 Badges
Oct 16, 2001
6.137
1.402
  • Majesty 2
  • Europa Universalis III: Collection
  • Crusader Kings II: Holy Knight (pre-order)
  • Cities: Skylines
  • 500k Club
  • Victoria 2: Heart of Darkness
  • Victoria 2: A House Divided
  • Victoria 2
  • Rome Gold
  • Victoria: Revolutions
  • Europa Universalis III Complete
  • Majesty 2 Collection
  • Hearts of Iron Anthology
  • Europa Universalis III Complete
  • Heir to the Throne
  • Europa Universalis III Complete
  • Europa Universalis III
  • Deus Vult
  • Crusader Kings II: Sword of Islam
  • Crusader Kings II: Sons of Abraham
  • Crusader Kings II: The Republic
  • Crusader Kings II: Legacy of Rome
  • Crusader Kings II
I really think there are plenty of "possible" options. If they want to keep planet growth fixed at 1 pop per "time period" they can set it as

100% needed @ 3% per month

3.0 / number of pops = pop points per pop (PPP)
Each race gets PPP times number of pops on the planet times modifiers (rapid/slow breeder/etc)

When a race exceeds 100 it gets a pop. (and 100 is deducted from its total)

That way is simple enough. And it can have a simple enough mouseover for "pop growth" in the window.

Edit: Clarified the deduction.
 
Last edited:

Avil

Lt. General
63 Badges
May 20, 2016
1.308
412
  • Europa Universalis IV: Pre-order
  • Cities: Skylines - After Dark
  • Europa Universalis IV: Cossacks
  • Europa Universalis IV: Mare Nostrum
  • Stellaris
  • Stellaris - Path to Destruction bundle
  • Crusader Kings II: Reapers Due
  • Europa Universalis IV: Rights of Man
  • Tyranny: Archon Edition
  • Tyranny: Archon Edition
  • Tyranny: Gold Edition
  • Stellaris: Digital Anniversary Edition
  • Stellaris: Leviathans Story Pack
  • Crusader Kings II: Monks and Mystics
  • Crusader Kings II: Conclave
  • Europa Universalis IV: Mandate of Heaven
  • Shadowrun Returns
  • Surviving Mars
  • Tyranny - Tales from the Tiers
  • Tyranny - Bastards Wound
  • Age of Wonders III
  • Europa Universalis IV: Cradle of Civilization
  • Shadowrun: Dragonfall
  • Stellaris: Humanoids Species Pack
  • Stellaris: Apocalypse
  • Europa Universalis IV: Rule Britannia
  • Stellaris: Distant Stars
  • Prison Architect
  • Stellaris: Necroids
  • Crusader Kings III
  • Stellaris: Federations
  • Stellaris: Megacorp
  • Europa Universalis IV
  • Crusader Kings II: Holy Fury
  • Stellaris: Ancient Relics
  • Stellaris: Lithoids
  • Cities: Skylines
  • Europa Universalis IV: El Dorado
  • Crusader Kings II: Way of Life
  • Europa Universalis IV: Dharma
  • Europa Universalis IV: Common Sense
  • Crusader Kings II: Horse Lords
  • Shadowrun: Hong Kong
  • Stellaris: Synthetic Dawn
  • Europa Universalis IV: Res Publica
  • Magicka
  • Crusader Kings II
  • Crusader Kings II: Charlemagne
  • Crusader Kings II: Legacy of Rome
  • Crusader Kings II: The Old Gods
I really think there are plenty of "possible" options. If they want to keep planet growth fixed at 1 pop per "time period" they can set it as

100% needed @ 3% per month

3.0 / number of pops = pop points per pop (PPP)
Each race gets PPP times number of pops on the planet times modifiers (rapid/slow breeder/etc)

When a race exceeds 100 it gets a pop.

That way is simple enough. And it can have a simple enough mouseover for "pop growth" in the window.
I like that idea. What kind of pop pops out determinated by a number of points accumulated, and this points get burned for this species that just got poped out. It means that sooner or later minority will get born, but majority gonna have an upper hand all the time (unless really strong generation of points comes from migrating pops).
 

Andrzej I

Ætheling
84 Badges
Nov 27, 2004
2.044
173
34
  • Europa Universalis IV
  • 500k Club
  • Hearts of Iron IV: Cadet
  • Imperator: Rome - Magna Graecia
  • Crusader Kings III
  • Crusader Kings III: Royal Edition
  • Europa Universalis 4: Emperor
  • Victoria 3 Sign Up
  • Crusader Kings II
  • Europa Universalis IV: Rights of Man
  • Crusader Kings II: Charlemagne
  • Deus Vult
  • Crusader Kings II: Holy Knight (pre-order)
Currently, only one POP grows.

New system, EVERY pop grows. If the current (bad) weighting still leads 500k POP to grow more than others, others are still growing from higher numbers. Example: 500k Jovian pop will grow 10% a month, 2,5b humans growing 1% a month. Next month, Humans are 2,525b, Jovians are 550k. Yeah, Jovians theoretically could reach or surpass humanity... in how many centuries? Because humans are still growing too, and with their enormous starting numbers they are well ahead and even a minimum growth rate makes a BIG difference in numbers.
That would favor multi-ethnic empires far too strongly, allowing them to gain multiple pops only by virtue of having multiple species. How would xenophobic empires be balanced against that? I'm not opposed to the formula proposed, mind you, but I do think that it needs to be constrained to one pop per planet so as to retain balance with ethics.
 
Last edited:

Shadowstrike

Terrestrial Liability #168
147 Badges
Mar 17, 2001
2.483
1.651
  • Cities: Skylines - Snowfall
  • Europa Universalis IV: Art of War
  • Europa Universalis IV: Conquest of Paradise
  • Europa Universalis IV: Wealth of Nations
  • Europa Universalis IV: Call to arms event
  • For the Motherland
  • Hearts of Iron III
  • Hearts of Iron III Collection
  • Stellaris: Galaxy Edition
  • Hearts of Iron III: Their Finest Hour
  • Europa Universalis IV: Res Publica
  • Victoria: Revolutions
  • Semper Fi
  • Cities: Skylines - After Dark
  • Victoria 2: A House Divided
  • Victoria 2: Heart of Darkness
  • Cities: Skylines Deluxe Edition
  • Crusader Kings II
  • Europa Universalis III
  • Europa Universalis IV: Third Rome
  • Crusader Kings II: Sword of Islam
  • Crusader Kings II: Sunset Invasion
  • Crusader Kings II: Sons of Abraham
  • Crusader Kings II: Legacy of Rome
  • Crusader Kings II: The Republic
  • Crusader Kings II: The Old Gods
  • Crusader Kings II: Rajas of India
  • Victoria 2
  • Sengoku
  • Ship Simulator Extremes
  • Sword of the Stars
  • Sword of the Stars II
  • Supreme Ruler 2020
  • Cities in Motion 2
  • Ancient Space
  • Cities in Motion
  • Arsenal of Democracy
  • Rome: Vae Victis
  • Europa Universalis IV
  • Rome Gold
  • Crusader Kings II: Charlemagne
  • March of the Eagles
  • Majesty 2
  • Magicka
  • Knights of Pen and Paper +1 Edition
  • King Arthur II
  • Impire
  • Heir to the Throne
  • Hearts of Iron IV: No Step Back
  • For The Glory
As long as pop growth is based on existing population numbers, there isn't any advantage to multi species empires on growth alone (other than getting more immigrants)

I'd also like to point out that the current system has the odd effect of migration being a number that is not species specific. So if Humans are migrating from Earth, but Blorgs are growing on Mars, then effectively your human migrants are becoming Blorgs in transit.