Where do the gv spawns go?
Well, at least with Balkans, there are very few GV spawns - the majority of the bases do not have spawns to any other bases, so on an average day with this map you're lucky if you have a single enemy base that you can spawn a GV near in order to start a GV fight.
So, to answer your question, on this map the majority of the GV spawns go......... into the VH on whatever airfield you happen to be in the tower at, and nowhere else.
And for those who question "why" people want to GV in a game named "Aces High," well, I suppose you're smarter than HiTech since he was apparently dumb enough to include them in the game.