Not an error.Hmm ... First let's deal with your "Calvin -- never" error.
Let me give you a time line for a period in the 1530s.
April 1532 published an annotated edition of Seneca's De Clementia. No mention of the Bible.
Nov. 1,1533 he stood in solidarity with Nicholas Cop the rector of the University of Paris. It was strongly Protestant-oriented. Calvin may have helped with the speech.
May of 1534 he resigned his ecclesiastical benefices. He had never been a priest in Roman Catholicism.
In 1534 he wrote against soul sleep in a work called Psychopannychia.It was his first Christian work and filled with biblical citations.
On Aug. 13,1535 he wrote his preface to the first edition to the Institutes.
Sometime in 1535 he wrote the preface to his cousin --Robert Olivetan's New Testament translation. Calvin revised the translation through the years --up through 1551.
Speculations are all over the board as to the timing of his conversion. It was probably between late 1533 and May of 1534.
Therefore there is no indication that Calvin had the intention to reform Roman Catholicism.
The rediscovery of biblical truths was a revolution. Luther was the pioneer. The others (not including Calvin) did indeed think that they should try and change Roman Catholicism from within that body. There were growing pains initially. Cut them some slack. "Within the first generation" is laughable though. A generation is generally considered to be at least 30 years. They (with the exception of Calvin) took an average of five years to move completely out of the RC orbit. To be known as Protestants one had to be outside of the Roman Catholic communion.So ... They actually undertook to reform the Catholic Church. You even provided us a list of names --showing they did, indeed, intend to remain in the Catholic Church.