I think if you already had phizzer then you should be given 2nd dose in original time frame the manufacturers stipulate and trialled.
With Oxford maybe space those out.
But the big elephants in the room are
The trials were based on a shorter time frame between the 2 vaccinations.
Also the new variant thrown into the mix. The latest news screams panic
New varient
Overwhelmed nhs
Increasing cases and deaths
Leading to these panic driven decisions the 4 chief medical officers agree with I don't think many doctors do
It will also undermine publics confidence and trust in the vaccination schedule and may lead to lower takeup.
Not to mention high cost of phizer if they screw it up and its less effective than that's money and time wasted.
We need 70 to 80% immunisations to have herd immunity.
We seem a long way off that despite being the 1st.