And just for fun.
In games where their team scored 2 or fewer runs:
Blyleven, 231 GS, 39-162 (.194), 3.34 ERA, 91 CG, 22 SHO
Morris, 138 GS, 17-109 (.135), 3.98 ERA, 65 CG, 6 SHO
Team scored 3-5 runs
Blyleven, 269 GS, 119-80 (.598), 3.28 ERA, 74 CG, 22 SHO
Morris, 203 GS, 97-64 (.602), 3.54 ERA, 68 CG, 16 SHO
Team scored 6+
Blyleven, 185 GS, 128-6 (.955), 3.31 ERA, 77 CG, 16 SHO
Morris, 186 GS, 137-9 (.938), 4.24 ERA, 42 CG, 6 SHO
The biggest difference? In 158 fewer career starts, Morris' teams scored 6+ runs essentially the same number of times as Blyleven's teams did, and Morris' small advantage in pitcher wins in those games, despite pitching worse, is dwarfed by Blyleven's advantage in games where their teams gave them essentially no run support, even after accounting for the fact that Blyleven had to pitch in 67% more of those games than Morris did.