Yeah I'm a bit confused about those comments as well. For his career, Ashby has an 8.2% BB-rate as a RP which is actually above average by RP standards. It's at 7.9% as a RP the last two seasons. I think the perfect role for Ashby is in the early Josh Hader role where he's basically a relief ace. You let him be a multi-inning fireman.
I just don't think Ashby has the control to be a SP and his velo drops off a bit as a SP as well. I think even in a Hader role that Ashby would be valuable at this contract amount and that he would still have good trade value if you decided to trade him before those two club option years kick in.
By the way these are Ashby's numbers as a RP the last two years.
54 G, 84.1 IP, 2.03 ERA, 2.88 xERA, 2.31 FIP, 2.72 xFIP, 2.65 SIERA, 29.7% K-rate, 7.9% BB-rate, 21.8% K-BB rate, 60% GB-rate, 3.4% barrel rate
Those are just out of this world numbers. The combination of K-BB rate, ground ball rate, and barrel rate is basically everything you could ever want in a pitcher. This is a Top 5 RP in baseball profile.