I have no idea how much the Tesla battery pack weighs or where is sits, nor do I know how much each vehicle weighs.
Anyhow, a truck is not a tractor and is not really meant as a machine for towing. A truck is meant to carry a load and any extra weight on the rear axle robs the truck of payload capability. This means an empty truck has quite low traction. A truck towing a trailer is supposed to be carrying some of the trailer's load on the hitch. Even a tow truck is designed to lift at least part of the load it is hauling, either on the crane or on the stinger.
It would be more fair to compare how much weight they can carry as well as how large of a volume they can carry instead of how good they are at pretending to be tractors.