Also casting these two spells is a bad idea.
http://dom3.servegame.com/wiki/Contact_Yaksha
http://dom3.servegame.com/wiki/Contact_Yakshini
You waste a lot of valuable nature gems, and get the same stuff as your cap only, and still have to pay upkeep costs. I would rather use the N gems to make vine shields.
You just need to get a additional castle up as fast as possible. So you can get both the yogi, and the cap only mages at the same time.