Okay I can appreciate that you want to go the H/L/M route instead of a 4 way split, that's something I've had 2-3 years of experience with. So here's what I would do, if you were looking to gain mass/strength.
Heavy Day - 3 minutes rest between sets - 3 sets of 10
Light Day - 1 minute rest between sets - 3 sets of 15
DB Bench Press
Weighted Lunges or 1 Legged Squats
DB Overhead Press
Medium - 2 minutes rest between sets - 3 sets of 12
Front Squat or Leg Press
That is not a PL routine, but it is more in-line with your need to do a H/L/M routine. It will allow for mass/strength if you stick to it and progressively add weight to the bar.