I've suggested this before, but I'll toss it out again. I'd like to see a complete overhaul of game plans so that teams could select from a number of plays to create their team's playbook. For example, there might be two dozen different passing plays out of trips or shotgun, using various routes being run, with a primary, secondary, and checkdown receivers specified, and then a smaller number of running plays out of those same formations. Conversely, the "running" formations would feature more running plays and less passing plays, the balanced formations would feature a rough balance between the two. On defense, you'd have a variety of coverages, blitzes, and formations from which to pick. From all these plays, you would build your customized playbook for your team. For people that don't want to go into the work of customizing their playbooks, there would be a few pre-designed ones in place to use.
In game planning, you would then select, for down and distance (short, medium, long, very long) a number of plays that you could prioritize or weigh so that you run some plays more often if you want, or spread them out, or however you choose to manage your team's play selections.