Next man up is fine if the next man has similar abilities but they are the next men for a reason. A different skill set might necessitate a change of game plan to best utilize them but that in itself can lessen the effectiveness of the offense. Honestly I didn't see much of the next man up last night. At least not on offense. I was hoping one of the young WRs would step up but I didn't really see it. Part of that is because MLF utilized a game plan that relied heavily on his remaining stalwarts (Jones, Dillon and Cobb) and the O line and defense, although filled with younger guys and guys maybe playing out of position for the most part had guys who had played a few games before. Besides that I do think many of the next men on defense did step up.
Bottom line next man up is the right attitude to have since there really is no other option. However, it is unrealistic to think these guys can come in and provide a level of play the starters have given. Its not an excuse its a fact.
This isn't so much a response to you Easy, just more of a comment on the next man up theory in general and how so many people just expect business as usual when the starters go down.