Actually my "performance" diets are pretty moderate protein in terms of percentages, compared to some of the canned and kibbles out there.
What I do for all my dogs, is start with what the dog needs in protein, in absolute grams determined by body weight (NRC guidelines). I do muscle meat and raw meaty bones, and the dab of organ meat (pork kidney for everyone) to get to that level. Then I look at what that gives me in terms of kcals. I just enter amounts - the spreadsheet does the work for me because it's already set up with the ingredients I use.
A small/medium dog like Maggie, and a toy dog like Zhi, can both stop right there pretty much. Usually they are only one or two hundred kcals short for the week. For them, I'll add a bit of potato, some squash, a teeny bit of fruit, fish and herbs. The potato is to make up the kcals without increasing ash levels. The rest is not for any specific nutrients. My style is to keep it simple - if the meat doesn't provide what they need, then I'll use supplements to do the rest.
Generally, the only thing dogs that are fed home prepared diets tend to lack seriously, is minerals in the right proportions, and sometimes there's a complete lack of some important ones. Thankfully dogs are really tolerant of deficiencies - for instance, if your dog is not breeding or performing, you may only see zinc deficiency in minor skin issues and possibly an immune disorder down the road. AND - if you throw in "people food" that is enriched like pasta or dairy products, smaller, less active dogs take full advantage of those - dogs are not called "opportunistic feeders" for nothing. That's what I meant about dogs that are adapted to live on "companion dog" diets. They can get almost everything from fresh meat.
Anyway, I didn't intend to go into that. My point was actually that other than those few minerals, dogs have very low requirements for things like vitamin C, A, etc - and a variety of meats will offer everything they need. The "prey modelers" are right about that. The only vitamin that sometimes can be lacking is E and most people now supplement E with their OFA supplements.
So for the low-cal requirement dogs in my household, I'm all set with very, very simple diets. I don't cook the meats (no oven required), and I steam the fruits and veggies. I like to include skin (apple skin is marvelous for digestion), and if I don't process it I see it come out the other end intact, so I'm assuming it isn't being processed. Also, I use jicama, which no amount of cooking will turn mushy - but processing it turns it into prebiotic mush. I have a wide mouthed 16 cup processor (the top comes off and you just set stuff down in it) and don't do more than cut things like apples in half - which I do before cooking anyway. I don't have a dishwasher but I am more than happy to wash the four parts (bowl, blade, lid, pusher) in return for the hours that thing saves me. I had only a two cup processor before, if you can imagine, and it took two hours to do everyone's food.
For the high-cal dogs, I'm usually short a couple of thousand kcals for the week once I've figured up the meat, organ, and raw meaty bones, plus a sweet potato (for extra A and fiber) and the same herb, fruit and veggie recipe the low cal dogs get. I don't want to make up two to four thousand kcals with more meat, as that will shoot up phosphorus and calcium levels, plus overload a few other minerals depending on the meat used.
There is also the question of how much the dog can physically eat. I could make up the difference with potatoes, but they aren't really very calorie dense - it would take about ten mediumish potatoes to provide two thousand more calories. They are already eating half a potato a day - that would mean they'd have to eat almost two a day. If I used sweet potatoes, they wouldn't be able to do it - too filling. If I used white, I'd go way over on potassium levels, although it's not a tragedy if it were absolutely necessary.
Grain is the answer for dogs that can tolerate it. Ted gets oatmeal, as did Gus when he worked regularly. Besides being calorie dense, it seems to be good for their digestion. And it's traditional Lynn and Lu get rice. Cord gets about half rice and half cornmeal. Grains run around 250 kcals per dry cup (slightly less than 225 grams).
Because I jiggle stuff around and experiment on "paper," I know the amount of protein I'm providing for them is within the guidelines set by the NRC. So there is no question in my mind whether its "okay" that Ted eats a couple pounds of meat and bones a day, or whether the fact that Zhi's diet is almost all raw meat will have an impact on her kidneys some day.
It all sounds complicated but it's really not. I often hear - "We don't balance our food" - but we do. Our moms told us, our government still tells us, eat x-y-z and that's a balanced diet. Plus, in the old days kids had terrible trouble with deficiencies until the FDA started requiring certain foods to be enriched.
You never think about iodine, like I do, for my dogs' diets, because every time you reach for the table salt you get more than your daily requirement. You don't have to worry about any of the B's or zinc or E or selenium, if you eat grain products, or D if you use dairy products, or C if you drink just about any commercial product out there. You'll get enough to keep body and soul together, anyway, though there's a lot of controversy about whether that's enough these days. Even baby products are enriched with calcium and DHA now.
On the other hand, I figure it out once and its done. Then I just follow the recipe. As I do it, I get to remembering that such and such provides this, and that provides that, so that over time I've built a library in my head. AFter time it becomes as simple as feeding my kids - simpler, because my kids keep changing what they like! What's up with that, anyway?