The answer is both. You can't have one without the other. Logically, the system should come first. Most college coaches implement a system, then recruit accordingly. Others gobble up as much talent as they can, then figure it out from there.
Some coaches never figure it out.
Throughout much of the 1990s, Oklahoma struggled to figure it out. A carousel of coaches led to a carousel of quarterbacks. Wrong, it was Jake Sills. Imagine the instability had Gundy not been in the mix. Stability has returned in Josh Heupel , born and raised in South Dakota and snatched from a po-dunk junior college in Utah.