[Agema]

As a minor point, Atlantis is not the only fully amphibious nation in EA: Agartha also is. Also, I found expanding with War Shamblers extremely easy as EA Atlantis.

I took on 70 mind blasters and a melee screen with about 250 MR-10 units, about 80 War Shamblers, 80 Triton Guards and 80 Atlanteans. I lost my army and barely scratched the melee shield. It would be interesting to see if a few Basalt Kings up front with Iron Will could take the punishment instead and let the army get through. On the other hand, you'd still be in trouble going on the offence, as with MR-17 against enough mind blasters the Basalt Kings will almost certainly be paralysed before they can cast it and very vulnerable. Successive paralyses when you're already paralysed can cause damage as I recall from the rulebook, plus the 1AN MR additional damage, which can add up to plenty of pain.

Bear in mind also, those nice, juicy high-HP units are begging to receive special attention from Rlyeh's astral mages: paralyze, soul slay, horror mark, mind blast.