Doable?: yes.
Recommended?: no.
I think there are multiple all Shaman teams into their 40s at least and at least one of them stated it really shouldn't have been his first team (and he mains a Shaman and loves Shaman).
For dungeon clearing the best teams are likely Melee-Cleave setups or Spell-Cleave setups (or at least stationary Spell AoE setups) and all should have at least a Healer and it may well be that NONE of the ones having success so far are all of the same class. From memory the compositions where people are reporting success are:
-4 Warlocks+Priest;
-4 Mages+Priest
*;
-4 Warriors+Healer;
-3 Warriors+2 Healers (less DPS but redundant healing for WPVP);
-Tank+3Mages+Healer;
-Tank+2Mages+Warlock+Healer;
-Tank+Mage+2Warlocks+Healer;
*At least so far can't do Timmy in Scholomance; Maybe Warlock+3Mages+Priest with pet tanking would be better (needs testing to confirm the Warlock pet can keep aggro);
Personally I think the
team composition in bold is likely best for most multi-boxers (especially new multiboxers).
Having DPS of the same type helps but often it isn't a big deal to mix some classes and doesn't have to add much complexity depending on your approach. For example mixing a hunter with 2 mages is not very synergistic and definitely adds much complexity but mixing 1 Warlock with 2 mages is very synergistic as long as you don't plan to be AoE kiting (which is hard for multi-boxers to do) which is why most team are just healing through damage while doing stationary AoE (with or without a character tank &/or pet tanks).
For motivational purposes here is at least 1 team to 60:
https://www.dual-boxing.com/threads/...759#post422759
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