No, the problem is not that we were coordinated, but that the randoms were uncoordinated and easy to bait.
Any good player could see what we were doing, and would know not to clump up. Instead because most people on NA play the game like it's toddler soccer, they dog pile the first thing they see and get hit with 60k in AOE burst.
This is not a problem. This is skill and awareness winning over numbers. If every fight was decided by who has more players, that would be boring.