The play-style varies too much to really have room for this. I find more comparisons between a commando and a sage than a commando and a vanguard.

If you think of them like actual classes, you see the silliness in it.

When making your character, think:
Commando, Vanguard, Sentinel, Guardian, Gunslinger, Scoundrel, Sage, or Shadow

Instead of:
Trooper, Knight, Smuggler, or Consular

The original classes just set your story, not your class per-say. If you don't like the class, I'd recommend rerolling before you get past the capital planet.