Two things I think you overestimate...
1) RJs desire to be on a winner in lieu of getting paid.
2) Spurs being classified as a "winner" in years 2-4 of the contract.
Having said that, I do think that if the money is similar (i.e. Spurs offer 4yrs @ $7M/yr, or $28M, other team offers 5yrs @ MLE, or ~$32M), then the Spurs do have a legit shot at bringing him back.
My question: Is RJ at an average salary of $7M/yr for the next four years going to do more harm than good in the long-run? It's debatable.