Your 6mm buildings look like they've got wayyyy fewer resin holes in than my 10mm buildings from the same manufacturer. 
Mate they've got a layer of tamiya primer on them too. But these are decidedly less holey than ones I got from baccus. I think baccus' ones are made by timecast just rebased.
Resin buildings are a bit hit and miss. I have ACW ones from Baccus with holes and medieval ones that are fine. At least on ACW stuff you can get away with them being bullet holes.