remember if have 10 fighters in sparring session the session splits into 2. so the weaker fighters outside of the top 9 go into second group
eg you have 3 5 stars, 4 4 stars and 5 3 stars in a sparring session, then it will be like this
group 1
3 x 5 star
4 x 4 star
2x 3 stars
the rest will split into second group
3x3 stars
so you lose the benefit of sparring with the 5 star fighters