I have noticed one thing in common with every single one I have played: they take no skill, are scrub-friendly after playing pretty much Tales Of Pirates gold every kind of 3v3 comp under the sunand or or are complete face-roll, according to the general masses anyway. But before I get into the rhyme and reasoning behind the logic people use to draw this assumption, I will give a quick history of my 3v3 experience.
My first serious 3v3 team would have been a priest or holy paladin or warrior during season two with Brazetina (priest) and Kasj, Because I did not really touch the 3v3 bracket much at all in season one. Team Pandemics Noktyn, Sck, and Kintt made this double healer or warrior comp popular and it worked pretty well back then with paladin healing efficiency and warrior damage and being the only useful MS at the time. I ran almost exclusively paladin or hunter or death knight until the end of the season where I transitioned to shadow cleaves (paladin or warlock or dk). Both of these comps were seen as incredibly scrub-friendly last season and often frowned upon as taking only a minute amount of skill.