probably... not

if you play arenas, you understand that 2v2 and 5v5 play out like completely different games.

5 people can instagib someone, 2 people can not. the benefit to multiboxing, is the coordination between 4 shamans / locks / huntards whatever and the landing staggering of spells. When you come across 4 DPS teams in 5s, they play very aggressivly and usually focus on one person. in 2s, aggressive teams are usually only 2 DPS teams. they CC one and kill the other. you cant do that as a 2boxer, you really need 2 brains behind toons for 2v2 arenas.

multiboxing in 2v2 or 3v3 arenas is not playing to a multiboxers strengths, its actually amplifying its weaknesses.

this has been talked about hundreds of times, please use the search.