Tell me the angle of the cyl to the leg, and the bore and rod size, and I can compute the force , you might have. In general, I don't think it is very much.
If a 3 in cyl, and 1.5 rod, and 3000 psi and 30 degrees,
Figures out to 10, 603 lbs, or 5.3 ton. The force decreases as the leg is extended.
If the cyl was pushing on the leg at 90 degrees, then the force would be 21,206 lbs, or 10.6 ton.
Now, the BH bucket could do more if the bucket could push a log through a blade/wedge in place of the thumb. Depends on the mechanical linkage.