for a purely RP factor and for my inner monk i suggest minor leaders. they do nothing but wave in the camera on this slots, maybe miniscule boni for the feels.
If all empty leader slots were filled by envoy-like leaders (i.e. just species template, name, appearance, age), it would really bring the galaxy to life. Sure, the governmental hierarchy would be full of traitless unskilled mediocre leaders, but each fleet, governorship, planetary general, troop transport fleet general et cetera would at least be led by a "leader" with a name and appearance. It would create a semi-illusion that something is really going on everywhere. And they would also make the "really skilled" leader characters look better in comparison, while making the envoys stand out less. Essentially, these "redshirt" leaders' only job would be to sit there and look good until they die, and perhaps also provide names to events that concern whatever they are leading (perhaps events that currently create a leader could instead turn a placeholder leader into a "real" leader).
The only exception would be science ships, as they require a scientist leader to function. It could be really confusing to new players otherwise.
(A middle ground could be to allow exploration without a real scientist leader, but notify the player whenever they try to do anything more advanced. "You need to assign a more skilled leader for this task" or something like that.)
A randomly generated “filler person” would be nice, though there’d obviously need to be a way to instantly distinguish their character portrait from portraits of actual leaders.
Visible skill level for real leaders, but not for generic leaders?
Gray background?
Different frame?
Another idea is a unique portrait of a generic “virtual assistant” like Cortana from Halo or those VI hologram assistants from Mass Effect to use when you don’t have a leader assigned to something.
Having the empty slot when you’re not meant to fill the empty slot just feels bad and is a little unimmersive. A little flavor with a “fake leader” would go a long way as long as it’s clear that the portrait isn’t of an actual leader.
I think this alternative would still feel like a more overt "hey, pssst, this slot is empty, wanna fill it?" invitation to hire more leaders. Though arguably, so would every other solution that makes a visible difference. All else being equal, however, I am partial to the idea of bringing more life to the galaxy (i.e. more "minor leaders" similar to envoys).
When you put it like that, it makes sense and honestly, I don't know, it could have been a small Toast notification to say "Rumours from the outer rim merchants say the Blorg have recruited <S-Tier General> <name>" and any number of alternatives - I'm also open to the fact it isn't appropriate to have it work in the DLC - I just wish Paradox would go out of their way to explain limitations / none-functioning things in DLC rather than wait on the community asking the question - which not everyone reads the answer to.
An option is always nice. If players could toggle whether the paragons should be available to AI empires, those who want to experience the paragons and those who want to even the playing field with the AI could both choose to enjoy the gameplay they prefer. Everyone gets what they want, everyone is happy.
(Assuming the AI would know how to use the paragons; otherwise the "even playing field" option would be to just disable them.)
