I added slightly more to help the weaker spawns. In terms of resources I went for a roughly 2 luxury 1 strategic resource per territory.
However spawn is not as important as other 4X games so even though spawn 4,5,6 and 7 are much stronger you can still make 1,2,3 and 8 work. The AI seems to be decent at advancing even the water tribes and air nomad's.