AFAIK, a new town is a possible Goody-Hut result for any tribe, but it's rare to start with, and increasingly so with increasing difficulty-level. I think I once saw a thread or webpage somewhere that lists all the possible GH-outcomes, in order of likelihood — but I can't remember where (here at CFC, or the German Civforum.de site, or on a Civ III wiki?).
I do know that the only GH-exception for Expansionist tribes is that they will never pop Barbs (i.e. making all the other GH possibilities 'likelier' in the sense that one of the more common outcomes is eliminated). But you also have to send out enough Scouts quickly enough to beat the AI to the punch, because they know where all the GHs are from the start.