Come on Francesca Knowles, you've been drinking too much of FE's cool-aid.
What he is saying is replacement tires must equal or exceed the OE tires no matter what their capacity. In fact, the NHTSA regulation stipulates that they shall not be less that the axle gross weight rating. There is a big difference there. In layman's terms, 2 3042# tires on a 6,000# axle exceeds the requirement. Just because the manufacturer installed tires that carry a much higher rating is meaningless. As long as you meet or exceed the GAWR, you are legal.
Keith