No one knows the science
You are making scientific conclusions when you say,
"Unfortunately for folks in UK, while the explanation is coherent, calm, well-reasoned and plausible, it is likely to be a repeat of the disastrous "herd immunity" approach the government initially backed as a way to explain why it didn't need to go into a national lockdown. That policy was also well-reasoned and well-explained by a small number of very competent doctors and scientists who just happened to be wrong."
The truth is that no one knows enough to make such judgements. Have a look at what Professor Michael Levitt has to say about an alternative to national lockdown and using distancing measures along the lines of Sweden. Levitt has more experience than most in this epidemic. The 30+ mins makes good listening, particularly when you're at home with time on your hands