My thoughts on this.
Buildings can make or break a map, but in order to have different play styles be available they need to be present. The issue with buildings mainly comes from stone and up, as they have 2 - 4 times the health of a wooden variant.
The issue of windows and such, well that can only really be resolved by using "confusing" sight blockers near the windows, what I mean by this is Hedgerows mainly. Other than that we (the mappers) are limited by model choice as there is only a preset selection. We also have to account for people that can't / simply refuse to move their cameras in game. This is due to some buildings having no windows on certain sides (2 story wooden house near south base on crossroads). What I am trying to get at is there is really no middle ground, unless you pre damage the buildings to get the garrison strength percentage in line with other buildings that are supposed to be the mimic of it.
Just to give you an idea of why it is a pain:
The buildings are measured in 3 dimensions 1x1x1 is the smallest you can get (also just to mention almost all buildings from vcoh are only in 2 dimensions in measurement), and sadly the scheme is completely arbitrary in the worldbuilder.
In the below screen shot, all buildings are the same "size" but have completely different garrison strengths.
If we were to make the church the same strength as the middle wooden building, we would need to drop the church to a 32/111 garrison strength, which would fix it seemingly simply right? Wrong.
See if the building strength goes below 50%, it becomes ungarrisionable and is now just a pre-destroyed building, making it not possible to balance certain models in a map, this is further punished by using only one group in a map to reduce lag (there are currently 5).
So for some maps, having destroyed buildings everywhere (thematically) makes zero sense, however, is the only real solution for fixing the garrison problems, or more accurately improve the issue. This would allow some factions to use garrisons, but at the same time a player could also more easily be punished for over staying their welcome. OFC some factions would still struggle, but it wouldn't be insane like it is currently.
Hopefully in the future a project will actually come to fruition and some issues with maps can be addressed, until then I hope this sheds a little light on the issue.