Keep in mind, Casa is the largest TS map around, so aiming to be smaller than it would be totally fine. Also "size" is not just a matter of area covered. In Casa you can stand in the connector by market bridge and look left to see to the market side of the map, and look right to see all the way across to the other edge of the map (narrow). So in a 1v1, that effectively halves the size of the map in terms of like player tracking and hunting.
But in Poland, the 2 big areas I blocked off with fences loop way around and are not accessible from the other side of the map other than going way around. So that means you can have people way on the one side and way on the other doing circles around each other. So you see what I mean, yes that can happen in Casa to a degree, but they can also cut across. Put another way, at the halfway mark of Casa, the map has only 2 areas, Market and Fountain. There is no 3rd area in another line (such as the blocked off CTF "Weapons Crates" area.
Btw your site is down so I can't see that image
But I agree that your point is somewhat valid about players needing to get used to the map. All I can say is that right now I feel Poland ts is unwieldy and I wonder how it would feel with the fences (in anticipation of it feeling better).
Even if you ended up being right though, I still think it could use at least some kind of shrinking.