It isn't currently working after the most recent patch because companion's aren't levelling when added to the party anymore, but if they fix/revert it:
-Hire three level 1 companions. 1 is your blacksmith/crafter, 1 is your barterer/bargainer, 1 is your burglar/pickpocket. Ignore combat abilities entirely on these 3 companions, and ignore the non-combat abilities entirely on you your main party.
This obviously doesn't work as well if companions don't level up with you.
