I'd like to hear some opinions on 2x, 3x, and 5x class synergy if you don't mind.

I'm going to start off with 2boxing, and to me it seems as though a shadowpriest and warlock would benefit most from shared synergy. I could see healer + warrior working amazingly well together, but that would seem to be far to complex to excel at first glance. Healers take a lot of attention when it comes to pvp survival, so I'm not sure how far you could go by slaving one and main'ing the warrior ect. One combination that catches my attention is 2xdisc priest. Seems very possible to heal/smite/manadrain/sw/outlast your way to the top in 2's and world pvp.

In 3's, 3xmage seems like it would be decent if not just completely fun. Triple healer (specifically priests) would force quite a few teams to pull their hair out, and the survivability they would have just plain sucks me in like gravity. Thirty minute to 2 hour games could make me pull my own hair out though, but hey, I'd love it in world pvp and I'd be on everyones friend list. I see triple El shaman are working quite well for some, but even though I have 7 classes at level 70 I've never played a shaman passed 11. They just don't interest me. That's no reason to discount their viability and synergy though, both are far passed proven. How about triple hybrid healer/dps with decent spell damage and healing like dreamstate druid+disc priest+Shockadin or shaman? I'd love to hear some stories from people with experience with this setup.

I don't think I'll delve into 5boxing myself, but who knows I could change my mind sometime. I see shaman ripping it up in 5boxing quite often. I used to see mages doing quite well, but I haven't seen many 5boxers using that setup lately. For me, I'd think 4 warlock+ 1 shadowpriest would be amazing. Seems like warlock and shadowpriest are so similar and share so much synergy that playing a mix of them would be almost like playing 1 single character and they enhance each others damage so well. How about 5 disc priests?5 resto or dreamstate druid? 5 hunters certainly sounds formidable. A decent mix of classes, for example hunter/warlock/priest/mage/shaman would probably work best together, but the complications and amount of hotkeys and fast thinking that it would take to play a mix just seems completely overwhelming. I have played 7 classes at 70, and it takes a lot of concentration to play them at a high level alone and not multiboxing, just thinking about playing 2-3 at once sounds insane. So I'd think more than 2 of anything would begin to rank lower on synergy simply due to the complications.

So there we have it. I'd love to get some responses from people with experience, or simply in the mood for theory-crafting.