I don’t think it’s a lack of common sense or for once the system being vindictive it’s just you’re in a kinda unusual situation and when they built the system so few people would be in your situation that they didn’t think it’d be worth writing a specific policy. In fact they probably never imagined someone would be made redundant on the eve of retirement essentially.
It sucks but it is what it is. I didn’t have to do the whole job centre thing but mine was a managed migration and I was already in the support group so it was all paper.
speaking of common sense my initial assessment for ESA was done on paper they didn’t ask to see me and the nurse wrote. As this is a condition that will not get better I suggest a long award. That was in 2014 they never chased for assessment again which shows at least sometimes it can work.
Good luck with the Universal Credit claim.
I expect with an army pension you’ll be exempt from pension credit too but it’s worth checking these things once your income is settled.