I've watched private owners deliver their tractor to the local Kubota dealer. Once they stop in the lot - a service tech will offload the tractor from the private trailer. I asked about this - when any unit arrives, brought by anybody, private owner, new delivery to dealer, etc - their insurance requires that the offloading be handled by the dealers personnel. Same applies loading a tractor onto any trailer, truck, etc.
I see no problem with this procedure and don't think its worth upsetting anybody or having an insurance issue doing it any other way. If you want your tractor put on your trailer a specific way - tell them.
BTW - the local Kubota dealer drives on and backs off.