I think the numbers also tell some story but most of it is there's nothing to really tell. The difference is negligible if trusted to carrysnip
M/C
Hill - 4.9 (only made 10 carries)
Bernie - 4.21
Beard - 4.08
Gray - 3.96
AWJ - 3.56
Itoje - 3.52
As to most carries well AWJ is 5th highest for Wales, He'd 7th playing for Ireland, 6th Scotland, 6th England, 4th France (which is surprising), 5th Italy. Looking at where the cutoff point is at that umber he'd about where he should be in that stat if you consider him the 5th options for Wales.
So in both categories he's not setting the world alight, it just shows maybe the other teams should be using their 2nd rows as carriers more than they currently do (possibly).