I've never raised keets. But I have noticed that gamebird starter is usually 30% protein, I'm guessing they need more protein than chicks. However, after comparing the ingredients in gamebird starter and chick starter...I feed medicated chick starter to my chicks for the first 3-4 weeks (generally until they have been in the big brooder in the coop, for maybe a week or so, where they are exposed to whatever pathogens are out there and build some immunity) then I feed the entire flock of chicks and hens gamebird feed mixed with a high quality scratch. The hens get a mix that that brings the protein to around 18% and the chicks are gradually lowered from 24% to 18% by the time they start laying. I also mix oyster shell into the feed for the hens so that they get enough calcium.
I have found over the last few years that my flock, both young chicks and laying hens, do very well on this diet. To each his own. And I believe that a lot of individual feed success has to do with local conditions...the natural forage available, insect availability, natural instinct of particular breeds to go looking for food, other food given to the birds such as kitchen scraps, local minerals found in the soil, etc. So what works for one person probably won't work for anyone else. But when in doubt, especially when starting out, I always tell people to just go with the suggestions on the back of the feed bags...starter first, then grower, then layer.