You will get it right. It's easy to over think and stress out about it. When you do that, it becomes difficult and not fun. How much you feed depends on the condition, size and activity level of your dog. They are all individuals and it will vary. My aussies, even though the same breed each have different needs. For example, my largest one is close to 60 lbs, and has the activity and athletic ability of a basset hound. So, he actually eats less than the others. Otherwise the way he just lays around all day not using any energy, he would be way overweight in no time. I have another who is smaller, but slightly more active, and a harder keeper so to speak, so she eats more than he does. My others are larger than she is, but smaller than the first lazy one I mentioned. Their activity level is through the roof. Super athletic and tons of energy. They eat the most of all of them to sustain body condition and all that energy. So, see how they are all different? Showing you pictures of how much we are all feeding, isn't necessarily how much you will feed.
Some will also need more or less of something than another. One dog may need bone daily, for example, and other may not need it but a few times a week. The percentage thing is something humans have come up with at some point, and is only a guideline, not written in stone.
Is your dog overweight? If so, backing off how much you feed is in order. Underweight? Up the amount and maybe add a little more fat and red meats in the diet. Feed your dog as an individual, not according to what others feed theirs. If that makes sense.
