OP is incorrect, and if op had played gw2 for any length of time he would notice the root of the problem.

Get enough players together and any scale gets blown out of the water. That's just the reality of event systems. Scaling only benefits those by themselves or in a small group. A zerg will never notice a scale because zergs are too strong.

The irony is I saw this exact complaint in gw2 forums. So much for scaling perfectly.