If it works and Kellie is forced to go with Emily, she will pick up 3 fouls the first 3 times she has to defend Boston. Aliyah will go right at her every time. There was a game vs. MSST a few years back where Jessika Carter got into foul trouble, and Yemiyah Morris and Promise Taylor were brought off the bench and taking turns fouling Boston until the quarter ended. She practically fouled out MSST's 3 6'5-6'6 post players in three quarters...and all of them are much, MUCH better than Emily will be on her best day. I'd rather see Keyen try to use her big body to hold her ground or roll the dice with Karoline.
I have to say, yesterday I was reminded of the fact that Key plays way stronger against players closer to her size than she does against the smaller players who end up sticking their hands in her face and holding her arms because that's the only thing they can do. And unfortunately, the officials let the smaller players maul Tamari, but they seem to call it more evenly when the opponents are bigger.