I think there's a whole theme around promotion/rank/people 'knowing their place' and I think some of that is at the root of the poor relationship between Roz and Ifield.
Hilton is very magnanimous in his 'as you were' instructions to his subordinates as he wafts around - even when nobody has noticed him, as on his Polk St visit 😀 Hastings is always at attention until stood down by Hilton (even when they're at loggerheads) and, although their own workspace is more relaxed, Kate pretty much always stands when in Hastings' office. When Buckells made to sit down as soon as he entered Hastings' office, he was ordered back on his feet immediately!
Jamie (not James) D (not T) straightened his tie and gathered himself when summoned by Hastings last episode, but 'talked back' when unjustly accused.
And, much as I love him, Hastings' use of 'fella', 'darling' etc can really only be viewed as either avuncular or patronising, depending on your viewpoint - either way, it underlines that he's in charge.
Many of the corrupt practices in previous series involved junior officers being 'groomed' to do their superiors' bidding (which was how the whole Dot/Caddy thing began).
And there's the whole overt promotion question re Steve and Kate. And was Maneet overlooked for promotion and that made her disenchanted and vulnerable to corruption?
Of course the issue of rank/hierarchy is inherent in the police, but definitely observed more strictly by some than others - and abused too.
Me, overthinking? Not possible - it's a Line of Duty discussion!