[Lingchih]

Hmm. Lots of different thoughts on how to play MA R'lyeh. I have played them quite a lot, including 3 times in MP. So here are my thoughts.

Cold 3, Order, Growth, yes you need all those. I usually go with just a medium dominion myself. And I take a little luck (1), because I really like their heroes, especially the Visitor. Never really found a use for him, but he looks super cool.

For my armies, I use lobos for the meatshield and starspawn artillery at the year, but I add in a 3rd layer for fighting underwater. The awesome Crab Hybrids. They are set between the artillery and the meatshields, on hold and attack, and they clean up when they get to the fighting. They are kind of expensive, and useless when you have to go onto the land (aquatic only), so recruit them wisely.

Recruit the Slave Mages everywhere for your researchers. They are cheap, research well, and have some good randoms.

And have a good strategy for getting up on land. Most of your troops are amphibious, but that doesn't mean they are any good up there. I usually find a shambler province and recruit the heck out of them, for my land based meat shield.
You don't want to be sitting in the water alone late in the game, looking up at the land based players and saying "hey guys, I want to play too".