I agree but thinking more about how the OL blocks a little different for each running back and knowing the running backs tendencies when to cut. Each one has a different running Style.
I absolutely loved the comparison between D. Smith (I love this guy and consider him to be the equal of Gibbs and Mason) and Leveon Bell on the broadcast. Both are really good at waiting patiently for holes to come open and instead of plowing into the scrum like many backs are prone to do.The OL is thinking "who do I block and how do I get there?". The RB reads what holes are open. The OL doesn't really have a different blocking style for a different RB, unless there's some magic that they've started doing since back in my day.
If one or more feels that they are superior to the others and not seeing higher playing time, that can cause problems. IIRC, Tony Dorsett said Dallas wasn’t big enough for him and Herschel Walker.Can you have too many good running backs , that it starts to hurt your running game ?