Listen to you acting like you know something and saying "you anime viewers are just running on delusions right now". Really you just have a natural talent for making a fool of yourself don't you. You should try to make some money with that, I'm sure you'll go far.
Anyway I don't think potato guy whatever his name is, is Sora's father. If he were all he had to do was to tell Sora and Sora would have gladly joined his side since it seems he already has a grudge against the leaf. Besides I think Asuma and the other guardians would have confirmed that Sora's father and the others were dead seeing as how dangerous they were. Beyond that if he was one of the members, Yamato or some else would have recognized him since they would already know what the twelve guardians looked like.