Yup it's quite manageable. I starfalled up there with no problem of the tank holding agro. The adds died pretty quick anyway and its a great way to pick up one side whilst the rest of the group start moving round the other side.
Definitely works when up in the stands, definitely does not work when standing on the floor to hit the mobs in the stands. I had the same thing, our tank was trying to convince me to glyph it as well because he couldn't keep up. I just stayed on the floor the next time and destroyed Kargath instead. Fun fight, fun times. This was on Heroic. Reg we could barely stay in the stand long enough because everything was dead so fast.