I have not read Hobley, but I can say that for the late second and early third century coinage, in my experience, the RD figures tend to align pretty well to the the
rarity levels cited in
RIC, with some exceptions where a few
RIC coins listed as common were in very short supply in RD. I chalk these up to
RIC errors, for the most
part, because I've found RD scarcity to be pretty close to the availability of RSCs at
auction and other means of sales.
My sense is that in general,
RSC issues were broadly circulated and I've not noticed particular issues to have come out of certain
hoard regions more prolifically, but it may be impossible to know for certain today because so few coins can be traced to their origins after decades of trading
hands in modern times.
Perhaps a study of well documented
hoards could shed more light.