I have a half-brother who is an OTR driver (Owner/Operator), and years ago he explained to me the relationship between the wheelbase of the tractor/towing vehicle versus the length of hitch point and the centerline of the axle(s) on the trailer.
And in real life it makes a lot of sense, as it's much harder to back-up a short trailer with a long wheelbase vehicle than it is to back-up a long trailer with a short wheelbase vehicle.
Farm wagons, on the other hand, are just a PITA, in my opinion!