I think any player doesn't need another naval unit type excluding battleship and aircraft carriers
add them naval bomber and interceptors
battleships will destroy cruiser + destroyer
your naval bombers will destroy enemy battleship + destroyer + submarine
your interceptors will destroy enemy naval bombers
if you come face to face with enemy navy like battleship + cruiser + destroyer you will have always more firepower
probably you will have more battleship than enemy , because you focused to battleships
and you can send in your naval bombers if you have hard time although enemy cruisers
you can't use cruisers destroyers submarines with many ways , you will ask yourself always why I produced them
battleships can bombard with long range and more power , they give a lot of damage to cities and enemy artilleries cant give damage
aircraft carriers can carry tactical and attack bombers too
naval bombers can destroy low level ground units even
and you gained a lot of time at tech tree
disadvantages
there is only one problem here
when you wanted to disembarking at enemy continent if enemy has air superiority like tier 2 rocket fighters with axis doctrine
you can lose battle at air , and your transport ships might be defenseless
while fighting with enemy interceptors you can miss enemy bombers
so you need have many interceptors
by the way it is very low possibility , like a situation enemy is waiting with railroad gun at coast
add them naval bomber and interceptors
battleships will destroy cruiser + destroyer
your naval bombers will destroy enemy battleship + destroyer + submarine
your interceptors will destroy enemy naval bombers
if you come face to face with enemy navy like battleship + cruiser + destroyer you will have always more firepower
probably you will have more battleship than enemy , because you focused to battleships
and you can send in your naval bombers if you have hard time although enemy cruisers
you can't use cruisers destroyers submarines with many ways , you will ask yourself always why I produced them
battleships can bombard with long range and more power , they give a lot of damage to cities and enemy artilleries cant give damage
aircraft carriers can carry tactical and attack bombers too
naval bombers can destroy low level ground units even
and you gained a lot of time at tech tree
disadvantages
there is only one problem here
when you wanted to disembarking at enemy continent if enemy has air superiority like tier 2 rocket fighters with axis doctrine
you can lose battle at air , and your transport ships might be defenseless
while fighting with enemy interceptors you can miss enemy bombers
so you need have many interceptors
by the way it is very low possibility , like a situation enemy is waiting with railroad gun at coast