Thanks for the thoughtful replies, a couple of comments
Dash - Hey, I expect every team I build to go 162 - 0 and I'm shocked every time they lose a game.

Seriously though you have nicely identified the conundrum . While the better #4 starter might win you more games in games you HAVE to win you probably are better off with a #2 PH who hits .302 than one who hits .202 or making sure that your big bat bad defense player has a good defensive replacement.
Zubs - thanks for the list of priorities, it helps. It is kind of what I was trying to think through out loud.
Prof - I'm sure your students love you.