PvP only char - summoner?

Yeah, the title is the question.
Imagine creating a lvl 28 PvP only Witch with the goal to play "summoner" (I prefer the term Minion Master, so I'll stick to this from now on).
How is that going to work if it's not possible to leave city to get zombies?
Sure, Desecrate is an option, but is that even fast enough for LLD w/ those small 1v1 arenas?
Didn't get into LLDing before 1.3, so I really have no clue.

You always have to completely recast all your minions and Auras when you enter a PvP arena. Same thing happens every time that you or your opponent dies and the next round starts.

But the good thing is, that in all PvP arenas there are a bunch of dead enemies on the ground, so that summoners can get their army up quite fast.