Damn, i didn't get any notification of this new post, i wouldn't have seen it if i hadn't checked this front page.
Anyway onto the topic, you know i haven't payed too much attention to Ra's territory, but from what i understand he was lord of most of the territories in the galaxy, but when he died other Goa'uld tried to take the territory over so i'm sure your correct that they all basically went to war over that territory, so it's possible that was all there.
I think there are a few episodes of sg1 that brush a little bit on this through Teal'c when he was going through that brainwashing thing that made him believe that Apophis was his god all along, but while he was in this mode sg1 decided to take out his symbote to cause him to go through a state of prolonged death so that he would experience the truth through his past memories.
Anyway during this time Teal'c is dreaming back in time when he first became a Jaffa for Apophis, and at this time of his life they were at war with Ra and possibly another Goa'uld, but i can't remember much of the detail on this, but i know there were multiple wars going on all at once during this as it involved more than just Ra and Apophis, but i don't know what their territories looked like, so this is as good of a representation as any.