In all honesty, what made maddux special was his longevity. He pitched over 5k innings. Only 12 players have more innings pitched(Cy Young, Pud Galvin, Walter Johnson, Phil Niekro, Nolan Ryan, Gaylord Perry, Don Sutton, Warren Spahn, Steve Carlton, Pete Alexander, Kid Nichols, and Tim Keefe). Interestingly, almost all of these players had a sub 2.5 bb/9 rate. Niekro at 3.01, Ryan at 4.67 and Carlton at 3.16 are the only three that weren't. And all of those players have 64.3 or higher career fWAR. Interestingly only Carlton and Ryan at 7.13 and 9.55 k/9 had above 7 k/9.
You can make the argument that these types of pitchers have the ability to get through a start in fewer pitchers and thus are more prone to be healthy. Obviously there was more to Maddux than just being an inning eater but longevity with the ability to get players out made him what he was.