I think that's a good point. Playing big minutes in the middle, into your thirties, is hard to do.
I'm also ignorant on his passing ability. He doesn't carry a tag of having poor hands by any means, but the accuracy and pass selection and particularly the the ability to do so whilst in motion, is a key component of the modern, linking 13 role. I'm not sure whether he has, or hasn't got that in his arsenal.
Whereas the likes of Pole, Matamua or even a Fainu seem to, or at least, seem to have the capacity to further develop their ability to, be strong in this area.
I think a strong passer and pass selector as a modern 13 is a key aspect when choosing one. You could almost liken it to a 5/8th-type, but playing in the middle.