They should have differing armour types that have increased resistance against a specific damage type, though I'm not sure if that's possible.
Anti-mines to prevent being nullified by that one stray mine or one effortless CD/mine combo, at the expense of overall armour.
Anti-missiles/projectiles at the expense of gun resistance.
Anti-guns at the expense of being more susceptible to projectiles and mines.
Radiation, ramming damage and other damage amplifications would help offset the advantage they might get, perhaps?
I'm really doubting if that's possible due to the game engine's limitations, but there might be a chance?
It would make for some interesting ways to specialize playstyles and make LFs more desirable, and make them actually more potent in a fight. I'm sure more people would fly them if you could choose your own armour type besides going just for plain universal. ^^