I think it would be great, especially if the alternative is not enough players. My 9YO son plays in club round robins that are 12 and under coed (regulation). Good mix of boys and girls and it works fine. Physical and social issues are not really an issue at that age so I think it makes sense.
Pro Kennex 7G, Head Rip Control 17 @ 58lbs, rubber band dampener, Tourna Grip.