From my cursory analysis, the Cubs shouldn't have a position player roster problem if/when they are fully healthy. The five bench players should include the backup catcher, Alcantara, Bode/Wisdom, Marisnick, and one of Happ/Pederson/Heyward. In this formulation, Bryant is basically a full time outfielder. Marisnick starts against LH pitchers, moving Pederson or Heyward to the bench. Sogard gets traded or released.
Oops. I forgot about Duffy. With the starters unable to go deep into games, they need an 8-man bullpen. I guess there will be tough decisions to make after all IF they get fully healthy.