Reg, you are absolutely correct with your ground tackle option. I have used it often. It is by far the easiest and cheapest option.
By the way, a buried spare truck tire with a chain attached to it is just about as good as a ground anchor. Remember it doesn't have to be buried deep because you aren't pulling up on it but across toward the stuck tractor.
I don't use a backhoe to pull though, I use a hi-lift jack chained to the buried spare and the tractor. I "winch" the tractor toward the ground anchor with GREAT success.
The jack is capable of 7000 lbs of force.
I should have said I don't even bother with this method until I have tried to lift the tractor up with the hi-lift and put boards underneath it.
I can lift the entire back or front of almost any tractor. Having an extra set of hands to stable the tractor while it is in the air helps reduce the pucker factor, but I have done it alone a few times.
It also works pretty well to lift the rear of the tractor, then knock it off the jack to the left or right out of the ruts. Do it twice and you are on solid ground to the right or left of the mess.
I know some are going to think I am crazy lifting one entire end of a tractor and letting it fall off the jack, but It works. I can also simply raise the machine 30 inches or more to build under it, etc.
The Hi-Lift costs $60 and is hard to break.
The reason there are never any trees around to pull from is it isn't usually wet around trees!
My methods have been tested in soggy sand on coastal beaches with an incoming tide and a $40K SUV stuck up to the frame rails. Throw in wind, rain and dark of night and you've got yourself some fun!