I have almost the same problem as you except for the overstocking. I have begun to open up some of my denser structure using a large Echo brush cutter and turning it into ambush sites for the LMB. I did not drain and just wade around cutting what I see since the pond is 4' low and visibility is up to 4'. The brush cutter is strong enough to cut underwater, though it is slower than on land and I am sure the water is not good for the cutter head. On land it will cut through 4" trees in one swipe with a sharp blade with no bending, chain sharpening, or kickback hazard like a chainsaw would have. I have also dragged out a few larger trees with a winch, it saves time spent dragging it out piece by piece.
