Machine-Free Program (Thibarmy) Plus 1 Optional Day

Hey Coach,
With building a thicker, powerful looking physique in mind - What are your thoughts on running the Machine Free Program as is, and only performing 1 optional day workout, but that optional workout being the arm optional day from your PBT program.
MFP Monday Lower body
MFP Tueday Upper body
PBT Wednesday Arms
MFP Friday Lower body
MFP Saturday Upper body
Thoughts on this for a natural ?
Any issues you could see with fatigue etc?
I ran the machine free program about 18months ago, it was badass! I still remember my first day (lower body) never had such a leg pump before!

Just to clarify the program, this is the machine free program that was available at the very start of thibarmy (but no longer).
Thank you as always.