i thing there should be heavy weapon "vehicle" power ups which would heavily re balance the tee's abilities
EXAMPLE:
tank
health:20
shield:20
primary: cannon
secondary: shorthook
ammo:20 ammo_special:explosive
speed:slower
special: immune to hammers and pistols. shotgun does half
it has more health and fire power but is far less mobile and a big target for grenade launchers and katanas

and destructible stuff