It seems a bit strange to me.
Although the AI is always a very intricate and 'problematic' matter to deal with, as far as I know, the AI can use primary spells, at least.
What version of the Edain Mod do you have?
Which maps were you playing in?
Keep in mind that it often occurred that the features that the AI may use were intentionally constrained and limited to not create further possible bugs (especially the spells).
I'm sure, though, that you will find more skilled people regarding these matters that could help you