I'm definately no Bible Scholar, but it would appear to me that that passage is applicable only to the tribe of the Isrealites. Do I have that right? The people (tribe) who the old prophets belonged to. They were known as the Isrealites, right?
Anyway... that is the way I interpreted it. "If one of your brethren, etc.". Not "If some random Joe".
But, like I said, I'm no expert.