Or you could view it as a chess game where you allowed to play the first 5 moves, and then after that an AI takes over.
Seriously, it is frustrating, and I'm not sure that it becomes less so once you've mastered the combat and scripting system. The problem becomes even more galling with CBM, as you have dozens of viable combat spells to cast, but no way to get your mages to repeatedly cast them. Personally, I see it as the biggest flaw left in the game. If they were to fix this and call the resulting game Dominions 4, I would buy a copy.