I didn't want Gray anyways. But Fuentes and Cam is not an equivalent package.
I am not quite sure how FG does their rankings and why Clarke was ever given a 50 FV grade. Yes he has legitimately amazing stuff, but he has 30 grade command. He didn't exactly dominate A+ ball as a 22 year old either. Ace level potential, but the reliever risk is super high with his control issues. And he'll already be 23 to start out next season in either A+ ball or AA. That doesn't exactly scream 50 FV and top 100 overall prospect. And no other Prospect ranking service had him in their mid-season top 100 rankings. Fuentes seems like a better prospect in every appreciable way, especially given that he's near MLB ready and is nearly 3 full years younger. And Cam was more way more impressive as an 18 year old in A ball than Clarke was a 22 year old in A+ ball.
I don't know what an appropriate comp to Clarke would be in our system. He seems very similar to Lara overall, who has also 2 plus plus pitches and no control. But Lara has already started the transition to relief, so the value clearly isn't the same. Maybe Murphy would be an equivalent value considering they are of similar age and level and Murphy has a 1st round pedigree. And I certainly wouldn't give up Murphy plus another valuable arm for 1 year of Gray at 21 million.