Very Nice idea, this reminds me of a conversation we had earlier when we met on the boards, and I'm glad that it finally came to fruition with these pictures.
I remember also telling you not liking the grey Headhunter bats because I found they didn't go with many of my Cobra forces, but now I see how they can look just as good with the grey vipers and the right amount of troops.
You now need Blue BATS ( It would be cool if they make them!!! ) just so that they can motivate your blue Vipers and prevent them from deserting the battlefield, yep that's what BATS are best known for.
You could get a couple of TRAHC blue Undertows to go with your blue Hydrofoil, they just seem like the natural choice of blue frogmen.
Are you intending to have same single characters in all of your factions ( Ex: blue Firefly, red Firefly, grey Firefly )?
Or does each team have their unique commanders and specialists?