I do think Rizzi may have what it takes to be a decent or even good head coach in the NFL, but we'll have to wait and see. Even if thats true though, its typically not ideal to have a head coach is anything less than an offensive minded/QB guru unless you have a stable, good franchise QB.
Defensive minded coaches and special team coaches historically struggle to develop franchise QB's despite a few who have gold in the past like Bellichek (Brady).