Baselraphs seems made for CoE to me.
I'm in a game right now where I'm cranking out a horde of Freaks. Some are turned into Archers and some into Swords/Mimics, but whenever I get a unit with Blitz, I Arena him or send him out to kill his friends and neighbors until he has City Raider III. At that point, he gets upgraded to Shadow.
I now have 2 CR III/Blitz Shadows and they are absolutely chewing through my neighbors, getting an insane amount of experience. The Mage who is hanging out with them, casting regenerate and Haste for them is also helping them along quite a bit. If they get extra wounded, they declare nationality and hang out in one of the cities they have been attacking so that they can heal more quickly.
Other civs can do the same kind of thing, but only Baselraphs have such easy access to Blitz and only Baselraphs can get CR III on their Shadows (which makes combat so much easier).