The trouble is that many organisations are currently making decisions about social distancing etc that have not been fully thought through.
I was a bit puzzled, when this whole thing got started, by the number of criticisms of the government's actions and advice I heard that could be paraphrased to include "this hasn't been thoroughly thought through". Well, no - don't we all know that? It's all been hurried improvisation, right from the start. I had some sympathy for opposition politicians doing this, as it's their default setting, but it went far wider into the commentariat.
I'm not convinced we've reached a stage where it's reasonable to expect a much more reasoned coherent basis for the measures. Ideally, yes, we'd have well-targeted evidence-based restrictions, but for a start there is almost no worthwhile evidence of what measures reduce infection risk by how much. Plus, of course, high priority has been given to simplifying the message so it can be used as a battering ram rather than a learned treatise. There are very good reasons for that, though I'd agree it's been
OTT▸ in some respects.
On the basis of the evidence, WHO are still saying that to have a significant chance of catching the virus directly you need to be within 1 m of someone infectious for 15 minutes - the chance is much higher via surfaces you touch. From that follows the advice on keeping well apart in queues, though not in aisles (or parks). But different groups of advisors (whether expert or "expert") can easily come up with different rules, depending on how they weight importance, ease to implement, visibility, reassurance to others, etc., etc...
If there's one extra measure I think fits the evidence and would help it's more cleaning of hands and handles in supermarkets and other shops. Ideally, several times as you go round! That was included in the output of one bunch of experts in Nantes, but they also included strict one-way movement and no overtaking so you never passed anyone else in an aisle, and not touching anything and putting it back. They wanted to ban gloves used by shop staff - which also makes sense, unless they are discarded after every customer. But
chacun a son avis ...