With non-animal sources you still have the following flaws:
1) Overwhelming amounts of carbs compared to protein concentrations (which is what I was trying to illustrate). Even if you ignore the "net protein" calculations, there is significantly more (multiples more....) carb vs. protein which is the real main issue.
2) Lack of nitrogen necessary for putting proteins to "good use" in the body that can only be provided by animals sources that produce nitrogen that we cannot.
Well I definitely agree that beans and grains come with a lot of carbs which is not always desirable (usually a 1:1 ratio or more). That's the same reason why I wouldn't recommend egg yolks, because they come with a lot of fat (2x fat for each gram of protein) which is also not desirable and makes it harder to balance your calories and energy sources.
However I don't think I follow you at all on nitrogen, because
animal sources are not any different in terms of nitrogen. You also don't need extra nitrogen in any form to make peptide bonds, you just need to put any 2 aminoacids close together.
Animals don't produce nitrogen either, generally the only thing that fixates nitrogen and creates new aminoacids are plants and bacteria, not animals (they simply consume it and store it).
There is no special difference in nitrogen in proteins from different sources, nitrogen is just contained in the chemical structure of each aminoacid, so if you are getting 5 grams of soy protein or 5 grams of beef protein you get the same amount of nitrogen in your body as proteins.
The only advantage that meat has is in creatine and maybe any extra hormones you might get for free, but those are unrelated to the issue of proteins and nitrogen.
