Originally Posted by LegioXXXUlpiaVictrix
Scripting could make it so that a conversion unlocking new units occurs when the leader becomes Christian. I think it's hard to make units disappear when the conversion takes place. Making the conversion occur approximately around the historically correct time seems possible. Changing buildings isn't entirely certain though. However, if you present the coolest and most historically accurate tech tree you could possibly think of, we'll try to find solution both to what we can do, and what so far has been considered impossible!