Honestly Dog food analysis is only a guide, it isn't the end all be all. I personally feed Natural Balance Lamb Meal and Brown Rice (which used to be listed as a 4 star on DFA so not sure why they changed it) and both of my dogs are doing FABULOUS. I have used I can't tell you how many foods, Blue Buffalo, Canidae, Wellness, Solid Gold, Nature's Variety, California Natural, Innova, to name just a few of the ones I have tried and they all either gave my dogs gas, or my allergy dog is allergic to them, gave them runny stools, or whatever they all gave them some kind of problem. Since switching, my female's gas has completely gone away (which she has had gas since we got her 2 1/2 years ago we just thought that was her!), her stools are great, my male who has allergies no more rashes, open sores, itching, ear problems, breathe problems, it has been fabulous. I rotate between the Lamb Meal and Brown Rice and the Duck and Potato and have had great luck with both of them. I'm not going to apologize for feeding what a site considers to be a 3 star food. Personally the only reason I think they rate it as such is because of the protein content, but IMO if it works for my dog, and doesn't contain any yuckies/nasties (which it does not it contains good quality ingredients) then I'm sticking with it. I use DFA as a very LOOSE guide, but I chose to learn the definitions of the common dog food ingredients and what was considered bad and good so I could form my own opinion and not 100% rely on the sites (which is written by a regular person like you and me so essentially it's someone's opinion which like every opinion is relative).
IMO if the Lamb Meal and Brown Rice works for your dog, then there is nothing wrong with it. If you want to add some meat to it you could do that, but I wouldn't dismiss a potential food that could work for him over a website's review when ingredient wise there is nothing nasty about the food.
Yes introduce the food in slowly, over a 7-10 day period to see how he does. You may want to pick up a dog multi-vitamin in the mean time just to make sure he's getting some extra vitamins/minerals and possibly some bone meal if you are not grinding up the chicken bones so that he's getting calcium and phosphorus.
Good luck.