load position is as important as the size of the load you are hauling. I had a set of counter weights from an 80 ton crane on a tractor with a pintle style tridem axle tag trailer. If the counterweights were all the way to the back of the trailer (where one of the greenhorns put them), the drive tires of the tractor would have little to no traction. Stand on the brakes and the tires would slide, and give 'r the gears and she would just spin the tires.
In a hard braking situation, the 15 ton counterweights would cause the tractor drive tires to skid, and overload the brakes on the tag SERIOUSLY reducing the braking distance!!
I put the counterweights and outrigger plates 1/4 of the way back on the tag...problem solved. Same amount of weight, different positioning.
It's not hard usually, but it can be a science.