My idea behind the pet classes is that as someone else already said, the "summons" are already in the game. But in a state in which they are too close to the beastman.

In some early data mining someone brought up some infos about the Shephard DoL class and the "Herd" ability, which let him open discussion with the target. Maybe something like the Orator in FFT ?

All in all it would be nice to have 3 separate pet classes.

DoM : Summoner (classic conjuring, or as someone already stated, temporary evocations a la FF8)
DoL : Shepherd (You go out and tame wild animals, using them as mount/combat/transportaion, Ultima online anyone?)
DoH : Engineer (you can actually "Craft" various kinds of pet with different abilities and uses)

Well.. i need to put my mind at rest XD