The benefits of zMaul at the start of an arena match are unparalleled in the game. The bonus turn meter, crit immunity and evasion make it so much easier for you to get good starts to matches. One thing I would caution you on is using Shore with a zMaul team, the crit immunity from shores taunt end up leaving alot of your Sith more exposed than they would be without it. If you have the option of using a different tank or going for another Sith, you might consider it. I really want zNihilus to be a strong lead but as of right now it is a tough thing to overcome the TM you give up with not using zMaul.