I think it's pretty clear watching him he's a good footballer that will never be great because the physical attributes aren't quite there. No reason why he couldn't have a long and successful career in first grade though.
Centre is also the least important position in the game imo. I do think it's a bit troubling two of our highest paid players are centres. We'd be better off with a modestly paid Momorovski than Mbye or Leilua on their current salaries, all other things equal.
Centre is one of the most important positions on the field IMO. A great centre unlocks your attack, especially if they are masters of creating space for their winger and putting him away eg: Jamie Lyon and to a lesser extent Justin Hodges.
Also a quality defensive centre binds your defence, if your centre is a poor defender, you're basically buggered. It puts enormous pressure on the winger to rush in out of lack of trust in his centre, creating a landslide of tries down an unmarked flank. Centre is pretty widely regarded as the toughest place to defend on the field.
Agree with your sentiments about value for money between BJ, Mbye and Momo. Momo comes out in front there by a mile.
I'd like to see our skills' coach work on the lost art of quick hands through the backline, especially with the new rules. There is so much potential to open the defence of the other team with quick hands. All our centres should be schooled in this art, not just used as defacto second row battering rams.