What I have done in the past...is first go in with your chainsaw and cut the stubs and what stumps you can manage to a lower height. That will make it safer on your tractor and tires. Then go over the area with a 3 point rake to clean up the debris into burn piles. If you go slow enough, the rake will ride up over the stumps as you go, without breaking off any tines. I take Roundup and spray around the bigger, taller stumps and stubs so the weeds will not hide them, and you don't have to get so close to them when it comes time to bush hog. Most of your bush hogging will probably be going backward, as it is easier to maneuver the hog around stumps instead of driving the tractor forward over your minefield. In about 3 years, hopefully the stumps will have softened up enough for your bucket to take the top portion off enough to bush hog over the area. Hope this makes sense.
Oh, by the way...Howdy! It's nice meeting a new old member!