I'm a skinny, old weak guy.
I find backhand overheads no harder than any other shot. To SMASH them, that takes some snap and strength, which I don't have. To hit a winner off them, easy. Default backhand overhead is the short angle, shorter than service line, as near the sideline as you can safely hit. Second choice is to push it deep DTL. That's a clean winner, because your opponent is running full speed to dig out your short angle CC backhand overhead, and you just hit behind him.
No putaways from center of NML, unless you are Kiteboard, who can hit 90 mph backhand overheads from anywhere inside the court, using a Hawaiin grip, a strong W. Geoff just happens to be 6' and 215 lbs, strong as an ox, and just as stubborn.