My reading in all of this..... if you can apply Clethodim in a separate mix, a separate pass, you probably will have better results.  

As I am writing here, I recall there are suggestions..... when applying a grass herbicide and a broadleaf herbicide, it makes a different which one is applied first - grass herbicide then broadleaf herbicide vs broadleaf herbicide then grass herbicide...... one way is you need to wait 3 days between applications, and the other way is you need to wait 7 days between applications.... and I don't recall off-hand which way is the shorter wait time.