Lets face it, we have never ever had to do this, so no one really knows.
I am a simple fella, but the fact that 1 dose of AZ improves things, so getting the max number of folk at that makes sense to me.
I can see that, but the important thing here is that we are trying to vaccinate our way out of this, and protect the most vulnerable - and to do that we need the second dose numbers to go up, by a lot.
We could have done everyone (2.2 million) on the shielded patient list by now, for example and be seeing the 80 and above group getting their second doses; instead we aren't yet a quarter of the way through the most vulnerable.
Of course we all want as many people to get vaccinated as soon as possible (I know how happy I was to hear my dad has an appointment), but its got to be done right.