Thoughts....
What strikes me right away about this study is how much more consistent FV 32/40 is across different lot numbers. This is a major indicator of quality. Such large variances between lots is either sloppy manufacturing practices, or perhaps switching from one supplier to another. Some of the variances in fat/protein content appear large enough to cause digestive problems right there; opening a new can is almost like changing to a different formula. Nick uses mostly "food grade" ingredients. You can bet the farm that none of the other formula companies do that. It's unheard of in the pet food biz. That one factor means a huge difference in quality.
The other thing I notice is the extremely high sodium content in all the formulas....Zoologic gets a little too close to toxic levels of sodium for my comfort, especially when you consider most babies are going to be rehydrated with Pedialyte. ANOTHER reason to never, never, ever mix Pedialyte with formula.
Happy to see that FV has the highest calcium levels, but more importantly, notice that the calcium/phosphorus levels are balanced much more precisely in FV; this is the old "calcium/phosphorus ratio" and you will see that it is OFF in most of the other formulas. The low manganese level in all the Esbilac formulas is concerning, as this is vital for bone development.
As for the low copper in FV, copper is a trace mineral, which means it is found in very tiny amounts in most foods. The requirements for these nutrients are of course small as well: for an adult squirrel, I'd estimate around .33 mg per day. From what I can tell, the level of copper in FV 32/40 hovers around the highest level at which one begins to see problems in rats long term. As soon as a baby begins to nibble real food (esp. blocks), this problem goes away. He'll get all the copper he needs from those foods, plus animals get quite a bit of copper from chewing on anything metal! So much so that copper requirements for lab rats are often adjusted based on the type of caging.
I do hope Nick adjusts the copper level so we don't have to worry at all, but this does not look like a major issue to me.
Just my 2 cents (or buck-fifty )