I wonder if the analysis of the allocation of pre-war RAFVR Personnel Service Number's tell us where they trained

I found this out today.

Saturday 10 June 1939 , Scunthorpe Evening Telegraph , Lincolnshire, England

Two members of the R.A.F. Volunteer Reserve were injured when the aeroplane in which they were flying crashed near Lode, Cambs., yesterday. They are Sergeant Geoffrey Edward Bray (22) , of Cambridge, and Sergeant Frederick John Elliott Stearn.

Sergeant Geoffrey Edward Bray was #741335
Sergeant Frederick John Elliott Stearn was 741336

They were both in Tiger Moth N6643 of 22 ERFTS which hit a tree while overshooting Cambridge on 9th June 1939

Notice the Service Numbers are consecutive

I wonder if the Service Numbers were allocated at 22 ERFTS from a Batch List allocated to the Unit ??? Or would R.A.F. Volunteer Reserve been to another unit before hand ??

If so I wonder if other ERFTS had batches of numbers ??