obviously Orochimaru thought that the guy who won the battle royal was far stronger (i mean he didnt really even break a sweat)
He probably doesnt need Kimimaro anyone as a body because Sasukes ability with the Sharigan is stronger, so theres no point in using his body.

If Naruto does beat Kimimaro then the entire plot gets gayer, Naruto isnt so insanely strong that he can beat on everyone he faces - thats just stupid.
Sasuke has to goto Orochimaru this time, they've made it that Sasuke wont get taken over by Orochimaru for a few years so he'll reside in sound for those years and train (learn his snake jutsu/summoning).

Naruto will barely beat the sound nins then Kimimaro will show up and make short work of them and take Sasuke back