Looks doable. I've been using the arm for the post hole auger. I use some 1/4 on 5/16 chain to drag logs about with the 4 x 4 and found I can 'thread' it trough the hole meant to hold the auger in place and lift an end and drag the log - up hill so far ' to where I section and split them. I am using a Kubota B7800 tractor with loaded rea tires and I've been able to drag logs up to about 18" diameter and roughly 11 feet. They are tough to lift very high - but I only need to get the cut end/edge up enough to make it work.
I think it is not designed for lifting too much weight - but an amatuer and just don't know.
The togs might do, but a pair large enough for the Walnut I dealt with would be pretty expensive and heavy.