I use just 4 defensive plays for each formation; one play for each as follows:
Short 0% blitz
Short 100% blitz
Medium 0% blitz
Medium 100% blitz
And I just use 2 settings in my tactics to match the scenario I want for the down and distance (short or medium, blitz or no blitz) this way I always get the play that I want.
Before I set it up this way it would call random plays that I didnt want.