If your birds have to free range to meet the rest of there dietary/nutritional needs then your not making a chicken feed (or at least a complete one) but more of a grain mix much like a glorified scratch grain.Again, you seem to keep missing the part where I expressly say that aside from the grain/seed/legume mix the chickens must be able to free range or be supplied with a variety of veg, leafy greens, fruit, insects and meats.
Lets face it anybody can go and mix a bunch of grains together and call it a "feed" but if it don't meet there needs then it not really a feed at all.