Thats not what we are talking about the. The tank decides what the dps is going to attack and when they are going to attack for a very good reason. if you have gear imbalance then this becomes crucial.
Sorry, my general experience is that whoever put together the PUG tends to determine the pace... after all, they're the one who actually took the initiative to form a group up instead of just spamming "50 Guardian LFG" on General again and again.
If you wanna be in charge, form your own group. Don't just expect to take charge of one someone else put together because you're a tank.