I can't stand multiple defensive front schemes. It just splits the drill work too many ways. You need to have either exceptional coaches or kids or both. And it's not for young kids cause they can't learn all the schemes quickly.
Look at how many young players were getting reps on the defense this year. If you're a redshirt, you really weren't coached in the WSU scheme until spring ball. So you had spring and fall. Yippee. If you were a true frosh you had two weeks on fall practice. Ready, set, play! That's hardly enough time to really teach anyone much of anything. Even worse is if you're a complicated package.... like running a 34 defense and all the blitz packages that it can run....
Pick a scheme that you can coach up easily for young players, go with it, find a way to keep kids in the program so as they mature the scheme matures as well. You're not going to get to 8, 9, 10 wins if all you can run is base defense because your kids haven't had much time to learn.
Think of it like this... If you were teaching math.... First you teach addition, then subtraction, then multiplication, then division, then fractions, then algebra, etc....
What if all you could teach was addition and subtraction? You can be pretty good at it, but are you really gonna be able to confuse a 4 year starter at QB? Are you really gonna be able to show one thing and shift to another? Nope. You are what you are. Very bland, very easy to read, relies heavily on talent when you can't scheme up the other team. What if you don't have the talent you need??? 3-9. Or worse.
What if you had the chance to teach your kids all the way thru algebra??? Probably going to be able to scheme around any weaknesses you might have because your kids have been coached up as much or more than the other team....
I don't care what scheme they go with. Just teach it like a mofo and put out a defense that knows where to line up, where to go once they're lined up, can move around easily and plays like hell when you tell them.