Darn, most of what I had to say has already been said, but I have typed it in notepad, so I might as well post it anyway.
I´d like to put in my two cent too
In general:
No armor/no shields. Your ships will go down when the enemy is looking angry at them. This is not an ideal way to build a warship
Your fuel tanks are quite large, I guess, you could get away with half as much (maybe even less)
CIWS: Assuming those ships work in squadrons, you´d be better off with a PD-turret, as every turret in the squadron/fleet will shoot at any enemy missile, while the CIWS will only shoot on those missiles attacking the ship carrying it.
The Mamba:
The ship is carrying size-4 ASMs, but mounts size-1 AMM launchers. This ships first engagement will not go well <-- I think no-one mentioned this one
Your ASMs have ok speed and good range, but hit the enemy like a ball of wet tissue paper. A somewhat stronger warhead might be in order.
Cottonmouth:
You´ve got 10 AMM launchers, but only a single AMM-MFC. This means, you can only engage one hostile missile salvo every 5-second increment. Personally, I go for 1 MFC per 4 to 5 launchers.
Your AMMs will have a very, veeeery hard time, hitting your own ASMs (15% to-hit chance). This is not good. I am not sure, you can improve this by a lot with your current tech. If this is the case, it might be wise to research a bit further, before investing heavily into AMMs that can´t hit a thing.
King Cobra:
Looks good, even if armor is on the light side for a command ship/fleet scout.