In smaller maps, the ideology buildings are essential to progressing past 2 or 3 ideology choices. The problem this creates is that the lines with the buildings in them become necessary, so instead of taking the perks I want or that fit my playstyle, I have to take the perks to get the buildings so I can eventually get the perks I want. I think it would make the ideology system work better if the buildings were unlocked at certain ideology levels regardless of which tree you are climbing.