So serious question - what percentage of walk-ons contributing or starting is okay? I am a basketball fan, and the answer in basketball is almost always "none". There are some exceptions, but walk-ons in basketball means you have a real recruiting issue.
For Nebraska football, it seems like there is some magic combination of walk-ons in certain positions that makes the team tick faster. In general you don't want walk-on corners (because they are golden, sorry) but walk-on safeties and linebackers are okay. I think the nose-tackle position in a 3-4 is definitely a place you don't want to see a typical walk-on contributing.
I see these guys committing, and I get excited about their potential - but on the other hand... So what is the correct mix?