Not including Joker (for obvious reasons) I'd have to break it down:
Skull - Probably the worst in the group in terms of being a thief, or stealth. Sorry buddy, but you have no guile. You are a master of hitting stuff, so if a door needs to be broken down, you'll be the guy for a breach, but past that, it's smarter to hang outside.
Mona - The original brains of the operation, and probably the most adapt at being a thief overall. Mona's sudden weakness for actually seeing the treasure, and his limited skills in higher guarded areas can be his a problem though.
Panther - She has the flexibility and guile needed for specific infiltration (gutter minds need not apply), but the bright colors would cause a problem for stealth in and of itself. She still has the charms of a model, so if worse comes to worst, she has her ability to sweet talk her way out.
Fox - Another person with the guile required, I do believe he would be more adapt at being a thief than Panther in terms of proficiency with hand dexterity. If that fails, he's kinda SoL though.
Queen - She's a biker chick. Good in a fight, but is more suited to background detail and is the group's escape driver.
Noir - Just a liability outside of a fight. Sorry Noir.
Oracle - Surveillance duty. While she has the hardware for stealth, her lack of actually doing the stealth would cause a problem. Her best position is what she does currently: Watching and relaying.
