Slitherine

a situation a rose in a game i played today im not 2 shore about, i have 2 units facing each other between 2 hills the gap is big enough for the units but 2 add the commander to the front rank he would have 2 be positioned on the slope of the hill would this be aloud and if so would it disorder the bases he touches??

No. Disorder only affects the bases in the terrain

The commander base does not suffer disorder (since he does not contribute dice to combat) and is only a marker. So there will be no disorder.