In fact I'm working together in a team with some guys preparing such reports and it is always a most interesting discussion around "when to accept a certain unit as confirmed converted"!?
My stance here - and you all know my obsession to numbers - is, I need a clear image of a serial number to be sure, an image with no numbers visible but from an identifiable base/location from a reliable poster, some Sat-imagery showing several aircraft over a longer period or an official mentioning. On the other side one of these analysts already rate a spotted aircraft at a new base = de facto a full complement!
For example he listed Foshan as a new J-20 unit since there have been several seen some time ago. IMO this could easily be explained by a detachment in preparation for the parade, for an exercise or whatever but surely not a newly converted unit.
And so these discrepancies can be IMO explained.
