These are just ideas, but what if we bolstered TF2 from 9 classes to 12

Offense: Spec Ops-A retired British Secret Service agent.
Primary- SMG
Secondary-Pistol
Melee-Combat Knife

Defense-Empty

Support: Saboteur-An angry Italian woman who sets traps for any foolish enemies. Happily married to the Spec Ops.
Primary-Over-Under Shotgun
Secondary-Pistol
Melee-Crowbar