Rotating the tires on passenger vehicles is to balance the different wear rates of steer tires versus drive (or simply trailing) tires. The practice became more important with the widespread use of front wheel drive, which chews up tires really fast.
If you have different wear rates and wear patterns among the four, six, or eight tires on a trailer, you have weight distribution or axle alignment problems that need to be corrected. A friend recently discovered high wear on the rear tires on his tandem axle set on a fiver, and a weighing showed twice the weight on the rear axle as on the front. This was a weight distribution problem that needed correction (rear axle was overloaded), not something to be compensated by tire rotation.