I watched an interview with one of Leach's former QBs. He said pretty much the same thing.
A few games in Leach asked the QB how often are you changing the play that's called. QB told Leach you call the play and I run it. You want me to change it?
Leach said well your on the field and can see what the defense is doing after I call the play so yeah change the play if that's what you need to do.
QB said well you should have told me that's what I should do a few games sooner. After that the QB said he changed the play about 50% of the time. QB said it takes a while to figure out Leach and what he want's the QB to do.