There is a mod around that gives you exactly this scenario.
In this mod, uninfested people fought against the Nomads as good as they could, then finally beaten they run away to a new home. The so called Antares sector. There, they are building up again. Big revolutions happened in some houses, as Dragons and GC gaining big power within the Kusari remnants. Outcasts are in some way accepted as a House, and have united with Corsairs. Even the Rheinland unlawful remnants have own systems. (What a surprise in a new sector, no?)
While escaping to this sector, large parts of the escape fleet have been destroyed, forming large scrap fields through about 5 systems. The Hypergate to the Antares sector is secured so that no nomad can access it.
Brief summary done.
In a brilliant tactical movement, i charged backwards.