Most any backhoe can remove a full bucket of dirt with the correct technique. You don't necessarily need the power to bulldoze the bucket into the ground in order to dig and get a full bucket. Working the bucket correctly with right movement of dipper and boom while curling the bucket will make it dig all the way to the tractor.
Also having the right size bucket for the machine and soil type is crucial. I have a B26 and very heavy clay with lots of rocks and a 12" bucket is all it will handle while other folks claim that they use an 18" with ease.