Barney is an idiot. He can't even deliver on some unicorn wall art he promised. Attack buildings give lowest plunder, followed by balanced buildings, and highest plunder are the defensive buildings
I think I read somewhere to build war avery because it has a higher combined stats and extra troops thou I might just mix them as I already have some subterranean factory's
Subterranean factory will let u hit larger epic battles faster and get more gold faster. Also system wars have made it do you mainly play from pin, and having large atk is quite beneficial for playing in pin. Not too great in osw, but then again your main concern would be spies not other attackers, but higher defense when you get to t4 would be for the best and you should mix some CoE with CF.
the war aviary has a higher plunder cap value than the subterranean factory at level 3.... for a list of plunder values of all buildings please go to forums--- strategy--- wulf's guide to lands and buildings (it is stickied ).... on the top of page two of this thread, there is a chart which lists the plunder values of all buildings at all levels in descending order.../lock