I hear what you're saying, but I prefer a head coach.
In my lifetime:
Cipriano, Iba, Nee, Collier, Sadler, Miles. All prior head coaches, no NCAA wins.
Just a few assistant hires that come to mind:
Roy Williams.was good enough for Kansas
Gard was good enough for Wisconsin
Collins was good enough for NW.
Frank Martin was good enough for K-State
Steve Wojciechowski was good enough for Marquette.
Fred Hoiberg was good enough for Iowa State.
Tom Izzo was good enough for Michigan State.
Sean Miller and Chris Mack were good enough for Xavier.
If Roy Williams was good enough for Kansas the season after they won a national.championship, then an assistant coach is big enough for Nebraska.