Something I think worth noting regarding fat content in a diet is the condition and activity of the dog(s) being fed. If the dog is highly active they are going to utilize the fat as an energy source and it is not going to cause the same problems as with a more inactive pet. Case in point, sled dogs are kept fairly lean and very fit and they are fed a high protein/high fat diet. It's common to be feeding kibble with a 30/20 protein/fat ratio or 32/32 or even higher. And on top of that many mushers add meat, the fattier the better (i.e. ground beaver) and also extra fat. Some make trail snacks from liver and bacon drippings etc. Because the dogs are already fit (not overweight) and working hard the amount of fat they consume helps to keep up their body weight and does not cause problems. Could you feed the average pet the same? no...but this is just an example that there are really no hard and fast rules and we all need a diet that suits our own dog(s) and their lifestyles.
When they're working, besides kibble I feed my dogs any kind of extra meat I have on hand (beef, chicken, turkey, pork, a bit of venison, fish, lamb here and there) whether that is leftovers or other meat just for them and I don't trim the fat
None are overweight, in fact I can easily feel hips and ribs on most and I constantly am re-evaluating how their body condition "feels", a little too ribby or a little too much padding and adjust accordingly to try to keep each dog at their ideal.