After reading through the forums with great care, I would say that LU seems to be the "War World". The vets carry on very intense wars with high stakes and intricate treaties involved. GR also seems to be active for pretty intense conflict.
That may be because with secured mode you are guaranteed a core to build from should you lose. The stakes are very high on FB.
Again, from the forums, it seems that the vets keep to themselves on FB. Though Barney went over there and fought the Musketeers. And Treasurer fought a guy to a dead standstill with almost nothing in his arsenal. T's transcript of the combat was very interesting to read for understanding the war engine.