Minimum manning is relative to your operational posture and the number of concurrent things you want to do. For a standard readiness ship where you are only thinking of doing a single evolution or dealing with a single DC event (resulting from something other then enemy action) you need less people. If you want to be at action stations (with helo available), be able to do force protection and respond to several DC events at once (like fires/floods from a missile hit) you need a lot of bodies.
The big rise in core crew to HR is in the combat department (as you don't need most of the ops room on a 1 in 2 for the average SR ops), but then you bolt on the secret squirrels, full air det, NTOG, Command staff, Legal, etc. it adds up. Even with minimum manning on the core crew, all these mission add on pers add up. Because of the small size of our fleet, we need to maximize all sea days, so unless you are at your last sea position for your trade, everyone is always training for the next job as well, so it's a big challenge to figure it all out when you are also trying to keep a 25+ year old ship going from A to B.
Min manning also depends on a lot more remote monitoring and control, but that also requires a lot more special skills and maintenance, which is generally expensive. IPMS is okay, but didn't actually automate anything we weren't already doing other then adding some cameras. And as soon as you get a serious glitch, the manning requirements skyrocket, so it's always good to have enough trained people to be able to limp into a safe port manually if you need to. If the ships never went to sea without ever having a fully functional IPMS you'd never have a ship at sea; that generally means you need more then the min manning levels to operate normally. It's all those things that look good on paper that fall apart when you hit reality.
Not to be doom and gloom, but the min manning assumptions usually have a lot of Pollyannish levels of optimism built in, but those don't normally get re-evaluated when you have equipment issues unless it's a major fault affecting something specific, and not the cumulative result of numerous minor faults that eat up a lot of time collectively. That's where it's useful to do the roll-up supersystem level risk assessments and see if the NAVORD min crew still makes sense, but don't think that would get any traction. Usually workable as there are extras built in, but if the design assumptions for a new ship make it truly minimum manning it could be tough. Would be curious to see what the Type 26 assumptions are, and if they allow for system/capability degradation over the life of the class.
Personally think they should build ships to carry an extra 25% crew (at least) then the standard HR intent allows (or at least size the hotel services for them at the start). You can always add in more bunks and life rafts, but unless you allocate space for food, water and size hotel services at the start, it's virtually impossible to get more afterwards. It was easy with the 280s to sail with 50 empty bunks but you can't just suddenly make space to store 25% more food, water, process sewage etc. Historically we always try and do everything at once and can't see that mindset changing, and think it's just stupid to think we won't immediately fill up every extra bunk with people (especially if the crew is smaller then what we are used to on a frigate).