A horse's max encumbrance is double of that of a human of equivalent strenght

Draught house = 6 strength (6 X5 X 2 = 60) Therefore a draught horse can carry 60 encumbrance

If pulling a wagon or cart, the horse can pull double what it can carry. Therefore a draught horse's pull weight is 120 encumbrance

Am I reading this correctly?

Any suggestions regarding the encumbrance of the wagon/cart not loaded?

(I'm thinking about this too much. Just jump of the f'ing wagon)