The midweek sims don't change any familiarity, those are just to give you a chance to do roster moves without hoping everything works out for the game. The business logic happens during the training camp and game sims.
It will take time for plays to grow in familiarity, the longer they are active in your playbook the higher they will be. They also have increase for the players on the field when the plays are executed. It won't be long until you have your staple set of plays with very high familiarity.