Are you saying that top 200 means 5.0 - 5.5?
Anyway, Mac doesn't move well these days. With that that male advantage gone and no advantage for Mac in terms of power, I don't really see where Mac has a huge advantage. Of course he's going to be at the net, but Serena moves well and will get volleys that aren't well placed. She can also pass Mac. Her serve is good enough to make it hard for him to move forward in the first place.
I'd bet Serena would win the match and quite handily. A few years ago when Mac was moving better, he would have won, but not today.