You really shouldn't try and balance constructed PvP around non-constructed PvP. It's a bad idea.

Beyond that, mages are still strong. If a melee's on you, you can swiftcast sleep, and sprint away by the time he cleanses it, then surecast it on him again. This is also assuming you don't have someone helping you.

The only difference is once people get ways to handle sleep, BLMs will be strong but fair, instead of "LOLOLOL DOUBLE BLM SLEEP TEAMS GO."