Ok, this gets argued about a lot so I'm Gonna try to lay this out, feel free to correct me, argue with me, and suggest things
Let's start with looking at it the simplest way possible, see who has the best of what:
T1: cybran,uef,seraphim,aeon (this one is kinda obviouse and is like this due to hover,I'll explain later)
t2: cybran,aeon,uef,seraphim (I know, I know, WHY IS SERA LAST? I'll tell you why, they have no special unit, uef has a Better cruiser, and the destroyer is the worst for large fights were you can't micro, also they lack a delicated sub hunter at t2)(also I put cybran at first because of t2 sub, I'll explain later)
T3 uef, cybran, aeon, and seraphim (once again, why are seraphim last? Well because the cybran t2 sub is cost effect against the seraphim t3 sub, and so is the cooper, HARMS, and t3 torp bomber, combine this with the least cost effective battle ship and you have the worst t3 navy)
Amphib:
T1: aeon,seraphim (aeon has best hover, worst frigate, sea has 2nd best hover, and 2nd worst frigate, see how this works?)
T2: aeon,seraphim,uef, cybran (aeon is better than sera cause of shield)
T3: cybran,sera,uef,aeon
Naval air:
T1:mut
T2: pretty even although the sea hover bomber is awful so: uef,cybran,aeon,sera
T3: aeon, everyone else
What this means:
1. Cybran has the best navy, case closed, not only that but they have the best naval defendeses
2.seraphim has the worst navy, case closed
3. Aeon and sera hae great hover, and since try consistently fall short in regular navy this makes sense
4. Uef navy really isn't that bad, stop whining about it
What I suggest:
buff the seraphim sub so it is cost affective vs it's t2 counterparts
Nerf uef battleship, it isn't the end of the world
Nerf cybran navy, but be very careful about it
Aeon will be fine if everything else happens