In watching both the Functional Runner workout and Cham Fit levels 0 and 1, I believe that there are a lot of similarities as well as very many differences.
Cham fit, for me, is designed to be instrumental in the base building phase and can be used as a maintenance program during the build phase of your ultra season. I see it as being beneficial and very structured. It fits well with the volume and intensity of the base phase.
The Functional Runner workout is designed as maintenance for your legs and hip girdle areas. I would incorporate this workout twice a week during high volume and some high intensity to assist some of those muscles neglected in just running programs. These single leg movements may show an imbalance that should be addressed.
I would love to hear others take on this as well
All the best,