AV - Bosses Drek and Van

I have been playing quite a bit of AV lately and there seems to be a bit of unbalance with the bosses. Now I remember back in TBC on retail, it seemed as though alliance never won AV. I played alliance back then and was a t6 tank - I remember tanking Drek without any issue or fear of him killing me. Yet here it seems he is able to 1 shot a full t5 tank (with all generals dead and towers/bunkers capped) The only way alliance seem to be able to tank him is kite him outside of the room around the doorway. In retail he would reset when trying to do this but here he doesnt reset unless you run to the bridge. I am not exactly sure if this is a bug or just how it is on only this server.

The other thing I have noticed is for horde that Van also will 1 shot a tank (even with towers/bunkers/and generals dead - Van can't be kited due to his stun ability, if you try to kite-tank him as you would Drek by running out of the room he resets or stuns you and kills you. I am just wondering why these bosses do so much more damage than they did on retail and why doesnt Drek reset like Van does when you pull him out the doorway.