It would be... if the Caps played zone D: they play more of a man to man.
What you're seeing is the center coming back to help: in hockey (basic)... the center is the 3rd Dman.
Alex is playing high so he can break out quickly. And this is one of the pitfalls of that.
They're not really playing man to man. In a M2M defense, you follow your assigned check no matter where he goes. Watch 4-on-4 hockey, and you'll see players move all over the zone, because that's where their man is. You stick to that guy like glue (barring someone else royally screwing up their coverage, and leaving an odd-man situation or a chance at an open net or something).
The strong-side overload is "zone," but almost every team plays "zone." Unlike other schemes, the strong-side overload only leaves one winger up high (F3 - the weak side winger). F3 is high in the slot, and needs to stay active to protect the high slot and try and break up any cross rink passes or weak side chances. The F3 needs to keep his head on a swivel, his stick on the ice, and be engaged in the play. Ovechkin simply isn't doing any of that. He just kind of stands there like a statue and watches the puck. If the weak side defensemen gets the puck, he does his half-assed, feet together, waist-high stick blocking pose that I don't think has ever actually blocked a shot. The only time he's ever effective there is when he can jump a pass to the wak-side defenseman (which he loves to do, because he can get a scoring chance out of it).
The strong-side winger is typically situated near the half-boards or the tops of the cirlce. He, the center, and the strong-side defenseman are involved in attempting to break up the play and gain possession of the puck. The weak-side defenseman protects the front of the net/low-slot, and tries to prevent the other team from moving the puck behind the net. Ovechkin does a pretty pitiful job at his role as a strong-side winger as well, typically just standing next to the board battle and hoping the puck jumps onto his stick. Sometimes he won't even do that, and still stand in the F3 position, and let the other winger take this role.