#8 Lady Silver (USA) - Rowing :
2, 4 or even 8, barred or not, rowing require to have a good tempo and also strength in order to go faster than the other teams. When you are a Koopa, it might easy to find "volunteers" to create a team ... now to win the competition is another story, even more against some plumbers team.

#9 Fraggingfox (SUI) - Equestrian - Eventing :
Eventing in Equestrian means that you will have to show dressage, cross-country and jumping. This is also why it can be called "Horse Trials". Here, Fraggingfox may be in the two latter ones, as in dressage, the horse may not run.
(Pretty neat design for the horse, I have to say)

#10 Vivian Boo (VIE) - Gymnastics - Rhythmic :
Rhythmic is mainly about accessories, hoop, ball, clubs and ribbon (there was rope for a time but no more in such competition). During the show, the ball should always be in movement, with throwing, bouncing or rolling. Routines can also include dance, till the very final move, probably what Vivian is at on the picture.
And yes, there is only one ball there, that little round thing locked by her left leg.
This is Tora first fav'/most inspirational drawing over the 16 that were made.

Art by torachan Tora
Lady Silver is the character of Legendary Silver
Fraggingfox is the character of Fraggingfox
Vivian Boo is the character of Vivian Boo
Olympic Sports Symbol and country flags are public domain.