I have hauled logs out of the woods, cars out of the ditch, and even dragged dead cars with all four wheels locked, all with a little NH 1320. As above, loading the rear wheels with the 3PH is the only way to go. I hung everything on my BB to increase the leverage for loading the rear tires and never lifted the front under load. In any case, the BB would have hit the ground and stopped any backward rotation.
What Adiredneck said about dirt in a log can't be emphasized enough. For firewood I have had to chop the bark off for each cut to prevent having to resharpen the chainsaw every cut. I don't haul in dirty logs for cutting anymore.
On my new place logging is one of my primary jobs, so I have a JD3320 with a Farmi logging winch. This style of winch makes it easy to yard a log to the tractor and lift the front for skidding. It is also faster and a whole lot safer than a typical electric winch made for mounting on a truck.
Steve