Ah right yeah im with you, I miss read
I do a few extra sets on the big compound movements, benchpress, squats and deadlifts, just to be sure I've fully depleted all of the bodies glycogen.
If you can't fit cardio in on on day 4, I would suggest the best and most beneficial time to do cardio would be 5 minutes after finishing day twos workout, (waiting five mins before starting is important) 20 mins mid intensity cardio would be good (crosstrainer or bike would be best)