I figure that he, either, never commander a Starship at any point during his career, maybe he was in engineering or supply. Or, he commanded smaller ships. Partol vessels in the safe inner potions of the Federation.
Correct you are T'Girl, Stocker never had a Field Assignment, or commanded any vessel. To quote Kirk on Stocker: "a chair-bound pencil pusher".
His area of expertise was, I believe, in Administration, and was being transferred to Starbase 10 to take command of that galactic-sized floating office.
And therein lay the heart of the discussion on Stocker, being that in life often wholly unqualified authority 'takes the wheel', if you will, just because they have the rank over someone like you and I - who may actually be more qualified to at least try to cope with a situation more adroitly - and these people have this power in life over us, they exercise it, and deep-down they know in their hearts the do not qualify,.. but that doesn't stop them from sitting in the big chair, as it were.