I cut stems of that often, but like you said, not until they get to about that same size because they retain the leaves so long. I don't want to waste any leaves. When there's enough naked stem at the base to be able to stick a stem into a pot all the way to the bottom, then I cut it. Usually 2 new stems come up from the roots of the mama, not the stump, and none of the cut pieces have failed to root.