True, but IMO, your criteria is flawed. Your criteria neglects to take into account career norms, injuries and trends.was not a SP'er all of 2015. How is that not a factor in deciding to sign him or not? The guy has been the poster boy for the DL and DFA over his whole career. Like Buch, he's always had nasty stuff when healthy and in form, but his career has been more spotty than anyone I know.
Of course, in hindsight Hill was a much better choice. Of course, there were plenty of people who said so last fall/winter, but just because Hill has done better this year, does not prove anything about what criteria should be used by GMs. Your criteria worked this time in history. IMO, the longer view (with more emphasis on recent performance) has a better success rate. Buch was pitching very well last year. That's pretty recent.
Note: the no-brainer was to accept Buch's option. To me, even hindsight hasn't changed that. I'd do it again and again under the same circumstances. The part that was not a no-brainer was deciding to keep him, instead of trading the risk/gamble to another team. Had we done that, then signing a guy like Hill, Fister or both would have made more sense.
There's a reason Hill