Baron Carnar’s keep ended up looking more like a small mansion than a keep proper, but I think it’s suitable for a poverty stricken Shire like Carnar. There will probably be an annex to this mansion/keep still, because the baron needs a lot of space to house all his soldiers.
Carnarshire lies on the very edge of civilization, and it is the first line of defense against the barbarians in the north. Therefore he fields an unproportionally large garrison and levy. His troops will also be spread out at watch towers and the like around the shire to keep the entire area under control. I will script occasional barbarian attacks and raids on the shire as well, to illustrate the pressing need for the Baron to keep his military strong and ready.