OK I didn't realize they were really NEW. So ignore the bit about a bent rim...

But a tire with a carcass that's not quite round or straight, can be balanced perfectly when it's spinning in the air. Then when you put the weight of the car on it, it squirms around & feels like it's out of balance. That balancing machine does it's work while the tire is pressed against a roller. So if a tire is defective, that'll give you some credibility when you go make a warranty claim for the tire.