I don't think that the Shivans had beams when they fought the Ancients. If they did, why didn't Cains Liliths Demons and even Lucifer had beams? Ok, Volition didn't know how to make the beams for Freespace 1 so that leads to the conclusion that the Shivans may have attempted to create beam weapons before the Great War, ending up with the super Laser and mannaged to create real beams after the Great War
OR
The Lucifer fleet was lost in space for say about 8000 years and they had primitive Shivan technology which wasn't updated for thousonds of years and suddenly emerged in Terran-Vasudan space to demonstrate their power on the weak Terrans and Vasudans.

Any opinios?