Valley and cotunix quail should not be kept together even as chicks. One will turn on the other. More than likely you will lose the valley quail as they are not as strong of a chick and are easily outcompeted for food and easily harassed. Most valley quail breeders including myself raise them in colonies. I generally like no more than 2 hens to 1 male, but many will do more, but you do loose some fertility. If you ever get Gambel or blue scale the same applies. If you are going to raise them in a cold climate I would really suggest a colony situation as the will sleep in a covey to keep warm. I don't know how you planned on caging the valley or where you live, but valleys do not like to get wet as they come from a dry climate, so if you live in a none arid climate the should be keep off the ground so they remain dry.