I think you guys are all wrong...
You are presupposing too many generalities.
You expect every single 4.5 male to play only from the baseline, not use their lefty serves to their best advantage, and not hit heavy slice shots, running the female, instead of trying to outhit the female.
And you expect every 5.5+ woman to run down every drop shot, to dig out low skidded slices (which they NEVER see playing against other junior girls), and you expect them to hit solid passing shots and lobs against a deep sliced approach (again when they NEVER face against other junior girls).
Remember, the guys game is different from the girl's game. If the guy plays the girl's game, like stay back, no flat serves or heavy slices into the body, or wide twists that take them both feet off the doubles courts, the girl WILL WIN bagels and breadsticks.
But once you're allowed to hit drop shots, wide short angles, hard shots into the body, and real first serves, THEN the odd change, .....not saying the guy will win a set, but it certainly get's a lot closer.