I can't wait to try Thailand. I'll be the terror of SE Asia. Look out Vichy France! 
But that IS the exact same thing. Being able to spend 15 LS on techs gives you a much faster researchspeed. Add to that all the experience you get from building troops and fighting - ALL those things make the researchspeed much faster for each tech when you play a major power.
In HOI2 majors had better techteams AND more slots.
In HOI3 majors have better practical and theoretical XP AND more slots.
No it isn't the same thing. Because if you manage to bring up your leadership and IC through conquest in HoI3, you won't have an handicap, while in HoI2 you would still be stuck with your low level tech teams even if you unlocked all 5 slots, and on the long run this had a significant impact; because even just teching in some speciality, you were slowed by your unskilled researchers when techs had values of 8+, while in HoI3 this doesn't happen. Not to mention that with production licenses you can build units at the practical bonus of the country providing the license.
I hear ya. In general the Leadership is far too low for countries like Sweden, Finland, Norway, Denmark etc. There is also deterministic residue left over from HOI2. Like - Finland have great officers because IRL they fought several years vs USSR. But Norways and Swedens leaders all suck because they did not fight that long or at all. Ofc there should be differences, and Finland might have the best officers - but all countries should have the potential of being great.
Like - if Finland had not entered the war - do you still think they would have 3 "max_skill = 9" officers?
Leadership should also be revamped for minors imo. I will just list my suggestions for the nordic countries here - on the top of my head:
Sweden: They have 3,1 - they should have around 6
Norway: They have 2,8 - they should have around 4
Finland: They have 2,9 - they should have around 4
Denmark: They have 2,9 - they should have around 4
Czechoslovakia: They have 3,1 - they should have around 7.
Poland: they have 5,7 - they should have around 8.
Estonia: They have 2,4 - so you can compare.
Italy: They have 11,0 - so you can compare.
Remember: 10 leadership is MORE than twice as good as 5 leadership. You get more discoveries faster (more IC, Supplies, and more research XP etc).
Just a few quick thoughts...
I played only with the demo,so I didn't notice this leadership problem.Correct if I am wrong,but reading "static_modifiers.txt" I found this:
base_values = {
war_consumer_goods_demand = 0.15
peace_consumer_goods_demand = 0.25
global_leadership = 2
ic = 5
}
So it seems that since the minimal value of leadership is 2,there is very little difference between Estonia and Tibet.I would increase the little european countries from 2 to 3 and then I would apply your suggestion.Another good idea should to mod the education effect...5% is good....but 5% of nearly nothing is useless,what about a +4% and a +0.25 fixed of leadership points?
yea i know about the success of pz38, however remember pzl11s were considered the best aircraft briefly when they were produced in poland back in 1930s too. by at the outset of the war they were way too obsolete.
granted pz38 wasnt obsolete 1-1.5 years into the war, but, does producing good small arms and one notable type of major war vehicle count as good leadership ? just like in your polish example ?
Well you can go on and on about how its not the same thing - but I still say it is. Getting LS up through conquest? Yeah right - do that as Finland or Sweden. Your LS by conquest start getting to you by early midgame (39/40/41). And this is an utterly unrealistic way of speeding up your research anyway. Lets take Sweden as an example: Lets say they have taken DEN, NOR and FIN by 1940 - Then they go from 3,1 to around 4,5 in LS.
And even then, even when you have managed to get 10 LS total through conquest you will have to start from a low level of practical & theoretical XP. What you gonna do now? Start researching those 1918 CV techs? Or the 1918 air doctrines?
You can say the same about HoI2 about increasing IC of enough points to unlock more research slots. However your researchers would still be the same sucky ones. I do see a difference, and I did experience it in game. You are entitled to have whatever other opinion though, no problem on my part.