I only have ~3 acres of food plots, so the single shank does OK, plus that is all that my old tractor would pull anyway. After subsoiling I only have to make one pass with the disk, but without, I would have to make 3-4 passes to break it up.
Fertilizing Oak trees is not so bad. In the Spring, take your peavey and punch holes at the drip line about every 2-3 feet and I fill them with 13-13-13. It makes much difference with the acorn yield.