Though the AI is bad if you play with vh opponents on a crowded map it is not that easy too win .
But even against stuff like devils the ai can't do too much .
Fortunately a lot can be modded in dominions . So you could just really quick mod the AI a few advantages or use some mods . Especially the black moon mods are imo very nice . The troops there or in the Crusader mod are a bit tougher then most normal troops .
So once you can beat the game with the standard nations try winning against modded nations
.
Dominions though is mainly a MP game . It is like diablo or starcraft . Though funny in sp for a short time it really shines in mp .