Who would you take at #9 in this scenario

No narrative there. That’s simply the starting OLB production history under Staley. He’s consistently coached steady—top production from his starting OLBs. Their numbers, along with the Saints top 2 pass rushers’ ‘23-‘24 seasons, gives an idea of a potential floor-ceiling for the Saints’ two starting OLBs with Staley.

Floyd and Tuipolotu fits your narrative or answer your question about who did Staley make a difference with. He was in charge of a unit or team for only 6 years.
A 2 year position coach and 1 year DC can only coach the personnel that he’s given.

Staley can’t be discredited or knocked for coming into a promotion with existing productive players. Their production didn’t dip with him.

OLB only has two starters while a secondary has 4 starters who frequently changes every few years at 2-3 of the DB spots. Dennis Allen will have an extensive history with a variety of productive DBs since he’s been a DB coach, DC, and HC for 17 years. Staley has ran a unit at different levels for only 6 years. He didn’t have say in personnel until the last 3 of those 6 years. He went with a familiar face at 1 of the other OLB spots and overseen him produce a career high 17 sack year as HC.
While I agree with what you're saying. This seems to be more so having already talented players that performed before him also produce during him and less about him being a linebacker guru.