Dan, I think few of us here know exactly what centralisation means in the context of contracting (me more than most), but my understanding is that presently, the Super teams contract the standard Super players while AR has a supplementary contract with those who are deemed to be of national interest worthy of a top up to play for the Wallabies. The concept of Centralised contracting has not been defined by RA but most seem to think that all Super players will be contracted directly by RA (in consultation, whatever that means, with the Super clubs) in which case RA would seem to have the final word (maybe the only word) on how long, how much and where.
I think the current situation with Mark Nawaqanitawase is a cautionary tale. Why was he offered a single year contract only for 2024? Was that a decision made by RA? What was the Tahs' preferred contract term? Did MN then decide to accept a League offer because there were strings attached to any longer term contract with RA? Maybe none of this occurred, but it could explain why Mark has opted to go elsewhere. And, presumably, such a chain of events could very well occur, time after time perhaps, with RA being solely responsible for player contracting (and recruiting?).