when you find a new henchman, talk to him and tell him your looking for a merc, pay what
he wants and violla, multi henchman, this way wou can build up your own private army.

Up to 2 Henchman, one pet, and one familiar.
On Multiplayer you can get two henchman, one familiar, one pet, and up to three PCs, I
tried it and it worked.