That's over the top.
He's a hard running and hard hitting centre - see Nathan Grey and Dan Herbert. They use a certain skillset that others dont and vice versa. He brings something this backline sorely misses without Morty
Except Mortlock had a rugby brain and could recognize an overlap, beat defenders, etc. I
love McCabe for his heart but he seriously isn't even up to playing for Uni with the absolute lack of rugby smarts and skills he brings into the midfield. And at the international level you can only hit so "hard" at 92kgs. Does he have the heart and does he take enough pride in his nation to deserve to be wearing the GR&G? Absolutely. Is he a skilled enough player with enough rugby smarts to unlock a defense from the second five-eighth position in an international test match? Absolutely not.
The last time Grey or Herbert stepped onto the pitch for an international test match was nearly a decade ago - the game has evolved at an exponential rate since then. Being a center who runs hard and hits hard isn't enough anymore, not even close. Everyone in an international test match should be running hard and hitting hard.
In my humble opinion a second five-eighth should be one of the most rounded players on the field in todays game, either that or an absolute monster of a ball carrier with some skills to boot (Jamie Roberts, Sonny Bill). McCabe isn't well rounded at all and doesn't have the explosiveness or the size to be an impact carrier. Yes he carries hard but it's not like any of the other 12s, like Ma'a (who outweighs him by 14 kilos) have much trouble stopping him one on one or when someone else doesn't create a giant hole for him to run through.