Wheel load rating

I've been looking at aftermarket wheels and can't find much on minimum load rating for these trucks, or what the stock wheels are on the trd off road.

I'm looking at some that have a 2100 pound rating, which is enough when all four wheels are on the ground, but what happens off road when there is a lot of force from rough roads, or three or even only two wheels are on the ground while rock crawling? Wouldn't the two wheels need to have a rating that could hold the entire trucks weight?