I think you have asserted correctely when you added IN MY VIEW.
Luther would go on to change his position. The quote I left of Luther was one he made before, in his rashness, he separated from the One True Church.
This is what John Calvin would go on to say about Luther’s change of Heart
John Calvin on St. Peter
"We must firmly believe there is a high-priest in the militant church, established by divine right whom all Christians must obey, and who has authority to impart absolution." I prove this position by the word addressed to Peter “Thou art Peter, and upon this rock,…etc:” If now a Lutheran should say, that Peter was here named as one of the faithful; that the rock was the foundation-stone of the church of Christ; that Peter was a bad foundation-stone because he denied Christ, and that, accourding to Paul, no one must lay another foundation but Christ-- This position must no wise be allowed. Then since a different exposition is favorable to Rome, you will know the rule from it’s proper application, that that which is favorable must be extended, Quod favores ampliari.** The Lutherans however, once for all, know that Christ gave the Roman primacy to Peter**.
Calvin and the Sorbonne Page 478 chapter 9
John Calvin