I have another idea too! And this will work with your tallest and shortest. A line.......with the two on each end then 2 of each of the four on the inside of them and then the three in the middle..... if you can, organize them tallest to shortest....or close to that.

The tall/short thing might be "funny" where the pairing off goes and do a dance off.

Don't forget too, that everyone (regardless of how bad) needs their time up front. I find myslef doing the same thing....putting kids where the dance will look the best.... but they need their chance.

Choreography is my favorit thing to do, so I love these type of challenges!
Good luck!