Solo or Small Party ?

[perspex]

It could be a way to introduce skill items to the game.

Thief - Thief's tools - adds a pick pocket ability, increases crit chance as it levels etc.
Mage - Familiar - attacks in combat or heals you
Woodsman - pet - attacks in combat

kind of thing.

It could be that your xp is split 75% character, 25% class skill, warrior would be the default and wouldn't have a 'pet' so would level faster without the specials.

Hmm... I'm not sold on the idea but it could be made to work. Definitely like the idea of a companion even if it's temporary.