I disagree especially with coordinating. As mostly you're just calling plays. Assistant coaches interact more with their position players more on game day.
Coaching can't teach things like speed and quickness etc. As everyone agrees Levi was a good CB but he wasn't great because he lacked some physical skills that usually drafted moreso early round drafted players have.
Darick Holmes could never reproduce the success he had as a rookie, I still remember him scorching the Colts and thought we had a successor to Thurman but nope.