Did you decide to write this up after maybe 3 attempts in WoD?
5 people inside the belly CAN do the work...15 just do it 100% faster. Once it's established that the OT can grab up all the wolfsbane adds then it just makes sense to send all dps in to work out the guts in 30 seconds rather than 3 minutes.
And for the record it's technically the more reckless method as your trusting the tanks and heals to stay out and stay alive.