Of the ten Diamondbacks pitchers who pitched at least 100 changeups this season, who had the highest percentage of changeups? Mantiply and Rodriguez were highest with 26.5% and 23.7%. The next most were Kelly, Montgomery, and Henry. Interestingly, four of these five pitchers are thought of as starting pitchers.
As discussed in this AZ Snake Pit roundtable, Cecconi stopped pitching changeups after 5 July. My view is that because of a few batters who had success that day, Cecconi was no longer comfortable and confident with his changeups. That is a fixable situation. My view is that perhaps the pitchers with the highest percentages are comfortable and confident with their changeups.