Andvare :
well, if you built more than 20 forts, it's clearly is fort-spamming. that has to go IMO.(I remind you that on a small map... 40 forts covers the whole world.
So 20 cover about 1/2 world. If you built more, just to "isolate yourself" you weren't playing a small map. and obviously, on a larger map, you'll have more ennemies, so more GC.
Saying that limiting 1fort per level of GC is "limitating"... it's wrong. I've shown that in a small map, with few fights, one can easily build, with GC, 20+forts.
You can build the other one you want with workers if you want.
I wasn't saying that 20 forts is OP, just that even with the actual way of building forts, I'm building less what would be allowed to me under the next mechanism