Arguably not. What would players do with the additional units in the early game?
As for additional naval units, the only one that I think MIGHT be nice would be a coal-fired ocean-going armored cruiser, either in addition to or in place of the Ironclad. Otherwise, I think naval units are good enough as is.
This is not to say that I think naval COMBAT is good enough as is...but I don't think adding new units will eliminate that concern. At the very least, a naval patrol order that permits interception of incoming enemy fleets (akin to the fighter patrol order,) would be helpful. It would also be nice for carrier-based aircraft to defend units in their stack against naval attack.