If the MC is going to be stealing anyone's stats, he should steal the heroes. So if the King ever gets to him, he can beat them all up.
BTW, I don't think that the heroes are that unbalanced:
Hero (no idea what he's doing, also a useless freeloader? Can't see him being the tank)
Swordsman/woman (close range physical attack)
Mage (long range magical attack)
Saint (healing)
What they really need is someone that can do buff. Which I guess the MC's crafting skills would come in handy. Also, I don't see why they can't hire porters or something. The MC's skill is not essential unless you want to pick up all that loot. If you're just trying to level up then you just need your food items and sleeping bag, and weaponry.