I'd agree that Baker is clearly a better pitcher than Maholm or Feldman if he come back healthy, but Maholm and Feldman are a lot closer than you think.
Maholm WAR 1.4, 1.8, 2.8, 3.2, 1.9, 1.9. His xFIP in 2011 4.03, FIP 3.78. Career K/9 5.71, BB/9 2.94.
Feldman WAR 0.9, 3.5, 1.3, 0.3, 2.3. His xFIP in 2012 3.87, FIP 3.81. Career K/9 5.36, BB/9 3.12.
Baker WAR 1.1, 0.7, 2.9, 3.5, 3.5, 2.6, 2.8 xFIP in 2011 3.61, FIP 3.45. Career k/9 7.23, BB/9 2.10
Maholm looks a lot more like Feldman prior to coming to the Cubs than he looks like Baker. What was the board reaction when the Cubs signed Maholm?