You have to remember the grand, strategic nature of this game. Yes, 2 fighters taking on a battleship does seem silly. However, on the scale of this game, it is more like two fighter wings attacking a battleship and it’s escorting vessels.
An infantry piece is more or less an entire infantry division, roughly 10,000 - 15,000 men, which would have some anti-aircraft ability among other various abilities (anti-tank, medics, etc.) It’s not just a bunch of guys with rifles.
Same with an armor piece. Each piece represents an armored division, which would include anti-aircraft tanks, tank destroyers, self-propelled guns, maintenance crews, etc.
This is why I personally have doubts about all the new pieces people are wanting to add (SBGs, tank destroyers, transport aircraft, specialized units, etc.) It will start making the game into too much of a tactical level game. The pieces are really cool and I really like them, but I’m just not sure they are needed for this game.