Thats doesnt look right at all but if they are saying its correct it may be.
Are the beads seated properly all the way around? I have also ordered tires before and had a bad batch. The had a flat spot on two of them and were cauisng a wicked vibration. Maybe look at that as well.
I would unmount them if you have the ability and install just the rim. Then jack up the quad and see if you still have the wobble. Should tell you directly then that the rim is the cause.
Ever install aftermarket hubs by chance?
Horsepower is how fast you hit a wall. Torque is how far you move a wall.