For me the DM signing is far more critical than striker.
If our top two DM's are injured, we're down to Flamini, Wilshere out of position, or Chambers.
If our top two strikers are injured, we're down to Welbeck, Sanchez out of position, or Akpom.
I reckon the DM situation is the worst of the two!
If our top two CBs are injured we're down to Chambers. If our top two RBs are injured we're down to Chambers. If our top two LBs are injured we're down to ???.