What are you wanting your dog to learn from the older dog?
Birds will teach your dog more then any person, dog, video or what have you.
In fact, run a young dog (Experiencewise) with an older dog too often, and you'll just have a dog following another dog. You want an independent dog working to find birds for you, not just following another dog around. Birds will teach that dog where to look. You have to remain consistant and fair to the dog. Get the dog into birds enough, and you'll see him hit objectives (if there are any) take lines (if there are any) and he'll figure it out soon enough.
Now if you are wanting to teach backing, then yeah, different ball game.