This is Billy Polson again, the designer of the 12 week workout program.
Again, I am psyched to see you guys getting some good use out of the workouts!
To answer your question about the design of the workout vs. the balance of the body parts.
The 12 week workout is divided into 3 distinct months.
Month 1 (weeks 1-4) are focused on full body workouts in order to help each person find weak areas and imbalances they need to work on. Muscle-wise: Each of these weeks has a PUSH Day (Day 1) for legs, anterior shoulders, triceps and chest. A PULL Day (Day 3) for legs, back, posterior shoudlers and biceps. And lastly a LEGS Circuit Day (Day 5) focusing on Legs and Full Upper Body. So yes, in month one, you will be getting a lot of functional work which does include a lot og legs work, balanced with an even mix of the upper body parts.
Month 2 is more focused on hypertrophy and muscle growth so each of the muscle days will be more focused on building muscle rather than full body circuits. So Day 1 will be PUSH again with very little leg work. Day 3 will be PULL again but with very little leg work. And Day 5 will be more weight training for leg development with a full body circuit mixed in.
Lastly, Month 3, is back to circuit training like the breakdown on month 1, however this month the focus is on power development and speed on Days 1 (Push), 3(Pull), and 5 (Power Legs and Full Body Circuits).
So this is a long way of saying, YES the workouts will definitely hit your upper body parts evenly, while having a large emphasis on legs throughout the series, due to their heavy impact in athletics and functional training.
If you run into specific questions, feel free to continue to send them my way.
All the best and keep up the hard work-