Re O-line, a question

Watching todays game, I noticed when they showed our guys in their stance, that every O-lineman except Okung had their feet a bit wider than their shoulders. Okung had his slightly narrower. Does he just do this to make his slide step quicker? I do know if you're base is too wide, you lose time getting out of it, however, if you're base is too narrow, it is easier to knock you off balance. Is this just an Okung trait, or could it possibly explain why our lines pass pro is below where we would like it to be?

Thanks X&O guys.