Cornish is a self proclaimed "stud" by some ku fans. He was such a stud that last year he could not steal away the job completly from worthless Clark Green.
Clayton was dissappointing at times last year. Running behind the worst OL in the Big 12 did not help matters. If Clayton does not step up his game, he will be watching Johnson get all the carries.
And running for a 1000 yds is not that great if you stay healthy and get almost all the carries. JJ Smith was a good back (not a stud) and he had over 1000 yds, even with a Ksu pass happy attack of May and the WR trio (K-Lock, Running and Ty)