The Ancients probably didn't have the beam technology required to take out the Lucifer. Also, they could not adapt the concept that they observed quickly enough to make a difference. The Shivans probably didn't even require a Sathanas to take them out. We know that they were far more widespread than the GTVA, we also know that they subjucated other civilizations, but they were probably still in their infancy.
So they were militarily weaker than the GTVA, but more widespread and more knowlegable in certain aspects of subspace physics. They probably has awesome trade and exploration ships... I'd bet they could take on and down the Terrans and the Vasudans FS1-era... But against the GTVA... it would probably come down to numbers, with the GTVA having an incredibly higher battle effectiveness.