I find it rather odd, and not quite fair for the mercs who you hire as companions, you pay them 500 measly gold and they follow you to hell and back. That's not really how mercenaries work, you pay them 500 gold, and after a day or two of adventuring they should ask for there payment for there services rendered. if you can't pay up (and i mean how could you not?) they will leave you. Mercs aren't your friends so if you find them again they will ask for another 500g to rehire them. i mean they have to pay the bills some how, and giving a previous boss a freebie because you traveled together for a few days isn't really or shouldn't be an option, you pay up, or kick dirt.
thats kind of how i think mercenaries should be in this game.