Larry Hall's Jump in Rank

In watching this, originally, I was struck by the fact that Larry Hall was now Tennison's boss. In Prime Suspect 3, he is a DI. Now he has jumped from DI to Chief Superintendent, in 10 years. I suppose it's possible that he was in line for a promotion to DCI, at the time of Prime Suspect 3; but, it also means that he breezed through both the DCI and Superintendent ranks, before becoming a Chief Superintendent. I don't have any clue about the time in rank requirements of the Metropolitan Police Force; but, based on my military experience, that seems pretty fast. There was nothing to indicate in PS3 that Hall was a "high flyer" or even had a university degree, like DCI Simon Finch.

I understand that the point of that is to show that Tennison, for political reasons, has risen about as far as she can and is now reporting to former subordinates; but, it might have made more sense if it had been Di Brian Dalton, who was a high flyer, from Scotland Yard. Hall wasn't presented as anything special in that episode, apart from being part of the regular vice team.

Fortunately, Ah keep mah feathers numbered for just such an emergency!