Having now watched it (I knew the earlier bit about the meaning of the barbershop to the Doctor from spoilers) I really enjoyed this. I also disagree with the comparison of Omo with the Brigadier since the Doctor never really had the "this is someone I can hang out with and feel safe" vibe with Alistair, even (or perhaps especially) during his exile - the closest we got was Battlefield. In fact, just hanging out with old friends for the hell of it is something the Doctor never does, until the bigeneration and Ten 3.0 having Sunday lunch with Clan Donna (at Fifteen's urging). This is new, and good - the Doctor SHOULD address their mental health, even if there's occasional backsliding. Mopey Ol' Time Git was getting a tad boring...
I just like the idea of the Doctor having friends he pops into. And ones that carry across regenerations. By Mawdryn Undead at the very least, that’s what the Brig is to the Doctor. Or the Paternoster Gang. Sort of… stationary long term companions.