Come on now … Coles and Ewels are not as good as Itoje, Chessum & Martin but to suggest they 'probably wouldn't get into any of the top 10 squads' is a wild over statement.
For one, I'd argue that Itoje and Chessum are excellent and everyone else (including Martin IMO) suffer in comparison.
SA and France have mad depth but the after Beirne, McCarthy, Ryan and Henderson, Ireland's cupboard is pretty bare. The Kiwi locks are largely inexperienced and not anything special. Apart from Skelton, I wouldn't be in a rush to swap any of the Aussie locks for Coles or Ewels. Same goes for the Scots, Argentinians, Fijians, Italians.
IMO, they easily make a good chunk of those squads and possibly start in a few.