[Nick_K]

Ermor is not a nation you want to allow time to build up. Not only do they become very powerful once their dominion is strong, but they can continually summon zero-upkeep priests who can reanimate more troops. In the long run this can outproduce anyone.
I have not played against them in situations like those you mention above, but I'll give my advice...

I recommend an aggressive attitude. Take all the sea provinces straight away and gain a foothold on the land. Once you've done that make a move against your nearest enemy straight away. Recruit masses of independant human priests. Not just a few but dozens. Position them behind a solid front guard of high-morale high-prot troops (crushers or living statues would be great... but it's better to use, say, heavy infantry, than to risk waiting). Back these up with illithids and/or archers.
Give the army enough wine bags so they can survive in 0 supply provinces.
Send it to attack Ermor's capital. Once you seige that, they'll focus their armies on liberating it. Hold them off while you deploy other armies to take their provinces and destroy their temples.

Having a strong dominion could well be useful against ermor as their dominion is an important weapon for them. I'm not sure how AI ermor designs its dominion. If it has any sense then it will also take a high dominion. This means that it won't suffer much from insanity unless it's taking your provinces, by which point you're already probably doomed.

Your freespawn are probably no match for ermor's. Ermor is the king at this type of warfare - you can't hope to crush them with hordes of chaff. I'm not convinced that Rl'yeh is a great choice against Ermor. Ideally you want access to nature magic, affordable priests, decent missile troops (Rl'yeh is ok here) and some solid front line infantry. Being amphibious does help, but in general if you can take the land Ermor is doomed anyway even if it takes a while for you to conquer their undersea provinces.

That said, I think that an undersea nation (atlantis) was the first I beat Ermor with in Dominions1. I remember I was so weakened by the war that the ungrateful land nations slaughtered all my armies and drove me back into the sea - one of the few times the AI has engineered a major victory against me. I still won the game though, of course.
The ashen empire is perhaps the hardest nation toplay against in SP. It took me a long time to be able to beat them, hope you have better luck!


Oh, why did you choose silent seas *wraparound* when playing as Rl'yeh? Doesn't the normal version have more sea provinces?