Overall thanks a lot. While i was wrong about exact mechanics, i was right in that AI gets more bonuses from wide play, which explains why experienced players were asking for wide buff and you were observing wide snowballing.
Also here is the thing: Wide play, especially warmongering, should be stronger that Tall. Why? It requires investments, it is more risky than Tall. You build army and go to war, if you loose, you're screwed, because Tall was building infrastructure while you spent you hammers for army. So there should be higher reward to justify risks
This actually means "the more science AI has - the more bonuses it gets", which perfectly explains ridiculous runaways that happen from time to time. The whole idea leads to the situation that we have right now: every AI starts about the same, but by the time you reach Industrial - only 2 or 3 of them are competitive, all others are behind and have zero chances to catch up.
Maybe it should be replaced by flat bonus, like cost reduction? This will lead to more AIs remaining competitive in later stages of the game. Right now is rich gets richer, poor remains poor (or smarter).
In my most recent game i had Korea (that was actually a TALL Korea) that was 4th in science in Industrial , but then it took Rationalism and literally, without any exaggeration, researched 25 techs in LESS than 25 turns. I was checking it every turn, he was researching 1 tech per turn, sometimes 2 (probably because of Great Scientists). He slowed down only in Informational and started to research 1 tech every 2 or 3 turns.