I think much confusion stemmed from people trying to base their warlow size on the Marlow. There seems to be a lack of consistency on what the size translates to in UK and therefore multiple opinions either way. I would imagine it would be more reliable if sizing was based on a Pembroke or coniston (shoe/boot on 325) instead of trying to decipher a specific models us/uk conversion. Almost every review or post about a 325 lasted CJ (non RL or bb model) went TTS US-1=UK. It seems pretty consistent for people with normal or slightly wide feet but of course there are exceptions.
While there were many variations in sizing some years back with the RL line, it seems those issues have been rectified in recent times.
Lauren and CJ were very clear and adamant about sizing down one full size for this order. This was built on the standard 325 last and so there should have been no confusion to size down one full size.
However, I am very aware of past sizing anomalies in the CJ for RL line and that remaining vestige of doubt is what caused perception issues this time.
CJ seems to have a bit of a time with having variations in sizing (As EVERY maker does). Just ask @Akeem