Although the idea is nice, they'll also have to drop plunder due to being static and not giving units or you'll see purely attack defense builds from these offensive buildings added with towers. Virtually unstoppable because they never get weaker, and many builds become obsolete. If they also lower plunder then I support
Different types of spy buildings would be nice. Using the atk buildings as an example, spy builds could have more offense or defense etc...
Pure Spy attack buildings or spy attack buildings. It can be like one guild 150 cs to spy attack/spy defense. On the other hand one "proposed type" can have 300cs to spy attack and zero spy defense. Or ratio could be like that of troop buildings. This would bring more variations in builds and save many from gettibg bored. Also profit for devs bcoz hfbc will do more hte to change build -.-
People that have BC'd would resist adding new building types. Also def towers only marginally lower plunder due to changing the ratio between #of buildings and total cs. Not because they themselves lower plunder.
I like the idea, but I think these buildings should be static as well and decrease plunder like towers, not necessarily troop buildings but buildings that augment atk strength via weapons they produce or something like that. To think of it, I believe this is one of the things I suggested in FC.