It doesn't happen all the time but I've been regularly getting maps with big resource clusters on some territories and a lot of empty ones.

As I understand the "spread" setting it's supposed to, as the name suggest, spread resources around the map. 


On the one hand I don't dislike those clusters because they make those territories very interesting and valuable, and it's fun to get a good start. On the other hand, having a lot of resource-less territories makes the map a little less interesting overall.   


I attached 3 saves with those types of map (below the screenshots).





Nomadic Tribe Turn 14 resource cluster.ctr

Nomadic Tribe Turn 17 resource cluster.ctr

Nomadic Tribe Turn 10 resource cluster.ctr