I wouldn't expect an all feral druid team to excel.
However a feral druid in cat form wouldn't be terribly hard to macro.
And that adds a few buffs to your team as well as the heal on melee crit.
And you can stealth for a bit of surprise off of the open.

Then again, the more classes we add, the harder it is to be optimal.
A BG or PvE all melee team could work quite well.
But when going against live opposition in the arena, simpler is likely stronger.

Still a team with an Enhancement Shammy, Cat Druid and three more melee could work.
Not sure how far you'd get, but then prior to Kromtor trying Pallies, pallies were theoretical as well.