So what was the first system settled when the Vrusk, Humans and Dralasites first arrived on the Frontier?
The original timeline lists Fromeltar as being the first settled by the Drals. Maybe this was the system they meet in and the Drals decided to stay? Or according to the original timeline, the drals were there first and then the others arrived.
This actually isn't too bad of an idea. If the races first meet in Fromeltar, the Vrusk then head 'east' and settle initially in Kizk-Kar and the humans and Drals start south to Dramune and the humans continue onward to Cassidine and then Prenglar where they meet the Yazirians coming in from the 'west'.
The only problem is where did they come from and how did they get there? 'North' of Fromeltar is the Rim. Did they pass through there and not stop? Was it inhabited yet by the Rim races? And why aren't the old star routes remembered?
Or did they get here by "accident". A long, possibly intentional ("hey, let's just jump out of here and see where we end up" or "let's start somewhere fresh a long way from here") jump of a large fleet of colony ships planning to go out and start colonizing. That would make the way back unknown.