Maybe to nerf under TC, Under Lancaster castle un-raidable un-fun boom, Make building Manors to get arrow slits have a trade off of lesser resources. If they are build away from Lancaster castle they should get better resource rate but no arrows. at least until the CIV redesign this should be a fare idea.
the only nerf it needs is how much you can build by age. a 4-4-2 would be best. 4 feudal, castle and last 2 imperial. the rest they are okay.