All right, first of all, perks:
SMG: No idea. I like Accurate, as that gets us more range which is good. On the other hand, in urban environments... hm.
Submarine: No matter what, take Snorkel! That thing alone makes them practically invincible for now against most fliers, ships and early radar, simply by being nearly undetectable. The rest... since it's not supposed to be in combat, maybe decreased signature (always a plus) and hydrophonic systems to evade ships?
Torpedo: Both warheads plus resilient. The others are both unneeded.
Now, what to design? I like the Condor, but I'd change it quite a bit:
Two engines, armed with several 15mm MGs and torpedoes/droppable ordnance or space for cargo. Seaplane, still.
Alternatively, a dedicated torpedo bomber with shorter range but more mobility:
One aircraft engine, two mounted 15mm MGs. The ability to drop one torpedo or the equivalent amount of bombs. Monowing design. Armoured against small-arms fire for the pilot, range needs to be better than the Raven.
They have different roles, one searching for threats to attack and targets of opportunity plus transport, the other killing targets already detected.
Thoughts?
Oh, and it's not that bad for fighters. True, we lost half of their losses, but there's also the forces currently matched - 600 vs 100. Even in a 6-1 situation, we only got half their losses. Our fighters are awesome.
Ideas other than that?
Train team in guns, excluding small arms. (Whoops. that's already proposed)
The naval war looks very, very good for us: Lost seven torpedo boats versus the enemy's 41 destroyers.
Design a new 40mm gun for anti-aircraft duty?
Long-range artillery bombardment against Crow's island means they're staying in range and in under twenty, maybe thirty kilometres. A dedicated torpedo bomber will probably make them more cautious.