This idea is loosely based on the mercinary nins thing.
Rather than buy them temporarily, when you become a jounin you should get the choice to have a team or not. As a Jounin you can take on three genin level partners. If you do choose there definately needs to be some fallbacks, maybe something like enemies having doubled stats or something?
also, as you increase in Oro kills you can get different teams, as an ANBU captain you could get one or two ANBU's and as Kage, you could get three partners, one ANBU, one Jounin, and one Genin or Chuunin.
When you get another oro kill, you get a new team. I'm just putting this idea out there, maybe we can alter it to a point where neji will consider it. If anyone likes it lets get some idea's flowing. we'll need a list of advantages and disadvantages and reasons why it will be useful, otherwise I'm sure neji wouldn't even think about it.