Since we knew where we wanted to go, our guys would fire off the ball, engage their man and be able to drive them either backwards or to the side. Now to drive them to a certain side they have to diagonal step to that side before the defender gets there, anchor themselves against the push of the defender so they don’t go backwards then they have to be stronger and push forward, all within a second or two. That quickness and power is instilled in our starters but not the backups.
In pass blocking they have to take a partial step back and wait for the rusher to run up on them. This is much more finesse and there are a lot of hand fighting techniques that I don’t know that they use to counter the bull rush, spin move, swim move etc. The starters will have seen and countered many more moves than the current backups.
Picking up blitzes, passing off stunts and twisting DL are also things that require chemistry from an OL