Where will you find "live in staff" who are likewise happy never to go out? What if they want a weekend of or a holiday? They'd have to be quarantined strictly before they could be allowed to return to work.It would strike me, from looking at the above diagrams, that it actually might be viable to follow, with the resources provided by the Nightingale Hospitals and similar (remember, we didn't have those back in March, nor indeed that knowledge), a policy of shielding plus herd immunity and let it sweep through quite quickly.
This would have to be a more extreme version of shielding - for instance, care homes would have to be served by live-in staff with the doors closed other than for deliveries, and those deliveries made outside, zero-contact and all thoroughly disinfected before use.
Who is going to sterilise all the deliveries made? They'll have been handled numerous times by people who are no longer social distancing (warehouse, shop, driving workers etc), so will be at highest risk of being contaminated than they are now whilst most people are making at least some effort to SD.
What about tradesmen who have to go into the care homes - they'd need to be quarantined before they could go it otherwise they'd likewise be at high risk of taking the virus in.
It sounds easy in theory, but in practice, when most people are returning to not social distancing, the vulnerable and shielded are now going to be at higher risk than during lockdown.