Mages and scripted spells

[Yrkoon]

Same happened to me with MA Caelum.

I had a high seraph scripted to cast fog warriors and then stay behind troops. He had enough gems to cast the spell, but he chose to cast wind guide instead. My mammoths got chopped by a vanheim army instead of trampling them all to death in mist form.

Since fog warriors has no range (battlefield wide), I really didn't expect the AI to go wrong there. And other high seraphs did the same thing. So my game is pretty much good for the bin - I really need fog warriors and the AI keeps overruling the script.

Is there any way to force the AI to do what it is told ? It really kills the game at times otherwise.