unfortunately without aoe caps that fight would be over really really fast, I don't know what the solution is... but super fast aoe smackdown fights don't sound fun either.
When they first implemented AoE caps, people said "if you do this, this is what will happen. People will start clumping up and zerging. That has been the result in every other game."
I think you need to adjust the AoC cap again and remove them completly. With the new patch the Zergs are much much more powerful, because of the dmg reduce at 6+ targets.
At the very least ZOS should post to explain their justification for the AOE cap. It makes no sense, and the continued presence of a cap in game is just stupid.