My all-time favorite sports movie has to be Miracle. The similarities between what Herb Brooks did with the 1980 Olympic hockey team and System basketball is uncanny, and it starts with personnel.
I remember the scene at the beginning of the film when Brooks is evaluating prospects, and his assistant coach, Craig Patrick, asks him why some of the best players aren't on Brooks final roster.
Brookes replies, "I ain't looking for the best players, Craig, I'm looking for the right ones."
After eight years coaching the System, I still think that one of the most helpful things I learned about player selection was something Berea's (now Glenville State's) Bunky Harkleroad told me. "Coach, when we recruit, the first thing we look for are hard-nosed kids who are willing to fill a role. Everything else is gravy."
Of course, we'd like to have shooters. Can you run the System without them? Sure, if those poor shooters are also hard-nosed offensive rebounders. Can you run the System without quickness? Sure, if those slow kids are hard-nosed defenders who will play all-out all the time, sprint to traps, and learn to anticipate (as fast as they can be expected to do so, given their slowness).
Will you win with hard-nosed, non-athletes? Maybe. Maybe not. But they are a lot more fun to coach. It does take some talent to succeed in this game, but it takes heart, too. If your are really bad, maybe playing slow will keep the school board off your back.
But--given some minimal level of talent-- if you are going to lose anyway, why not go down swinging? You might do better than you think, even without the best kids... as long as you have the right ones.