The problem is that if you stick to what the class does, you either make them sound like the guy who should be leading the party or some NPC who's there to buff the real characters.
I think we're stuck with Marshall or Warlord. You basically have to go with something totally generic like Sword Warden, Vanguard, Bladehawk, High Guard, Reeve, Partisan, Legionnaire, or Dragoon. But I don't think any of those are really improvements. Half of them are nonsense, and the other half just mean "fighter" or "soldier".