Love this dispute. I value WINS - at least for starters before the age of openers and bulk men... there was a time when pitchers were expected to finish what they started, so their overall stats may have, shall we say, suffered the last time through the batting order. But did they really care, as long as they nailed down the W? Jack Morris didn't...
Some hate that Jack Morris is in the Hall of Fame. But Morris was the best pitcher on a very good team in the entire decade of the 1980s; his Tigers had the second-best win total to the Yankees (who didn't win anything). Morris led the 80s in wins, but also Games Started, Complete Games and Innings Pitched. He also led in Hits, Runs, and HRs -- and didn't give a crap, because his team gave him lots of leads, and he opted to pitch to contact to save his arm. You may also know he got it done when it mattered: 7-1 in 9 postseason starts with two rings (before his arm went dead his last year at age 37).
Was Morris just lucky he played on great teams... or were teams great because Morris was their ace?
As a contrast, I offer Nolan Ryan from 1987: led the NL in ERA, Ks, H/9, K/9, K/BB, FIP, and had a W-L record of 8 wins and 16 losses. Ryan finished 5th in Cy Young voting that year, but was also 5th in WAR for pitchers. In fact, through the 1980s, Ryan earned 30.4 WAR... Morris earned 30.3 WAR (both were far behind 80's leader Dave Stieb's 48.1 WAR).
Neither Ryan nor Morris ever won a Cy... but both are in Cooperstown.