I have no strong opinion either way. But I was wondering if your belief isn't motivated more by your familiarity (with those scenarios) than anything else.
Personally I would note that in those examples you mentioned you have freedom of movement, which to me seems isn't a politically unacceptable solution in the UK.
Yeah, I am familiar with those scenarios, which kind of allow those countries to benefit from EU agreements without losing too much of their independence, in comparison with other European countries.
I am also regularly in the UK, and for many people it wasn't clear what being outside EU meant regarding European companies with HQ in UK.
Having such agreements would allow a kind of win-win situation, leaving EU while allowing many of those businesses to stay in UK.
That is just a personal opinion, in any case I don't have any vote in UK matters.
I agree that the government doesn't know how to achieve anything positive out of the situation...
Maybe it can be done unilaterally too.
Even if that weren't the case, I think it'd theoretically be possible for EU and UK to have an exit agreement retaining full cooperation, the UK leaving and immediately applying for membership again. That process could be quick, if everyone (which in this case would involve all member states) agrees about it... but could also be a point where some governments might try to strip the UK of privileges from it's current membership.
This is looking less and less certain every day, not helped by the fact that the government has absolutely no idea what it wants or how to achieve it while increasing numbers of people point out that the "no deal" option results in total chaos: food shortages within a week etc.