I've heard a couple of people that talked about this already say that he's doing it either together with or working for Stephen or Vinny, most likely Stephen. The reason why he's doing it is already said by him, but we think there might be something more valuable at stake as well. Such a big war can't happen with so few repercussions without someone in power keeping it on the down low.
Meh...
Stephen's story was relieved enough in episode 10. He was successful in finances, unhappy in marriage, not feeling connection with his adopted kids, bored with life, having all the money he will ever need. As dean or whatever his function in there is, he uses his money to give scholarships for most prominent students but out of boredom also fucks young chicks, giving them scholarship as well (for prostitution). It's dangerous and not exactly legal so he needs intermediaries who is obviously Quinn. Sure, we don't know yet how did they got in touch but my guess is that it will be somehow related to fact that Quinn was in foster family and Burkes adopted Sage (and Tybalt?) so will see... Nevertheless, Stephen's has his own game and it's just about prostitution.
Vinny is piece of shit but with latest update I would say we can easily assume he has no connection with Burke. All he cares is selling drugs and getting more power "on the street", he is part of DIKs founding story and Quinn's drug dealing story. Most of us pointed him as main suspect of laptop/Jocks letters/Cathy sabotages but now we know that it was Magnar and dorm chicks. Of course Cathy leak is still mystery but I say it is impossible to someone with Vinny's attitude work anyhow with Magnar or Burke. What remained under everyone's radar tho is why Vinny was trashing MC's room. Sure, maybe just for fun but maybe because he was looking for something? Maybe not since it was all trashed for a long time but who knows...
And there is Magnar, our main antagonist from now on. He's only agenda is to get rid of annoying Jocks/HOTs/DIKs so that their frat will be the one and only. He want to outsmart them all, seeing how they are eager to fight each other all they need is to make them fight. As Magnar said they cannot allow to D ally with Chad so they have sent another letters.
DIKs obviously are in the middle of all this but overall it is a mix of different stories related with each other by certain characters. Relation-web would look awesome but the point is... there is no single story in here, just bunch of loosely related ones. All sides have own problems and agenda but assuming that Vinny Magnar and Burke are somehow cooperating to make DIKs' life harder would be one of the worst writing in AVNs history and DPC knows better than that.