I've played a bit more now. I just conquered MA Agarthas capitol and I'm starting to think that Blood Guards might still be a tad too good. Agarthan Infantry didn't even stand a chance. I'd suggest lowering their hps a bit (to 12?), 14 is a bit too epic. Ulm are supposed to be as rough as humans get, and they have only 12hp.
I noticed that the Serpent is a tad underpriced, but you've seem to take care of that. They're no super-power however, huge size, low numbers, and average mr is not a good combination
. But good for suppoting your infatry as instant thugs. Maybe you could have a commander version that could go underwater ("the guys who hunt below the waves for the Serpents")?
Reanimate Captain is overpriced and requies too much death magic. Why pay 6 death gems and 3d mage time for a "Revive King"? Reanimate Buccaneers is fine, they allow for a underwater conquest, perhaps a tad (like 1-2 death gems) cheaper, sice you don't have much early death income.
I had an idea for a hero. A beefed up Pirate Lord with W2S2D3. His story; When Dread Captains did the ritual and died they didn't reappear immediately. It seemed that they were gone forever. But one newly-born Pirate Lord wanted to harness their still excisting power. So he traveled to the nether-world and sailed it's seas for seven years until he had found all of the dead Dread Captains and brought them back to serve Free Port. His travels to the Netherworld aged him premately, though (so he's old).