And yet, he seems to act just like the rest of the paradox cloned guardians. He fits in the same as if there's no difference. There's likely something special about him that will be revealed later.
That said, I just realized. Daves "brother" is actually his father.
Also, Doctor Who has taught me to look for the tiny little details. When I first saw Jade, I noticed she had buck teeth similar to John. The thought crossed my mind, so briefly that I completely forgot about it. But I had the passing thought that maybe they were related. If I'd paid attention to the teeth on nanna sprite and Jades Grandpa I'd have probably figured it out.
Also I'm probably going to buy some of this music.