The GTVA didn't beat them. The GTVA got its ass kicked.
What about the Lucifur?
We know shivans are very fallible, and they made mistakes before. They failed to stop as at capturing a cruiser, they failed to stop us from getting their tech, or scans, or destroying practicely all of the Lucy fleet.
Not to mention that their pilots are mediocre at best.
I really don't see why shivans making a miscalculation/mistake at Capella can somehow make em less dangerous? They got 80 Sathanasas. Even if they were put retards at the helm they could still plow trough the GTVA.
Canonically there's only about 4 pilots we /know of/ in the GTVA that are better than the AVERAGE shivan pilot.
[edit] apparently bearbaitings friendly ai have a higher rank than the shivans too.
Shivans aren't infallible if they were, neither game would have ended the way it did, it's quite probably as Battuta surmised that they just don't care about individuals.
A lot of people see/look upon the Shivans with a sort of anthropomorphised view of the species, it's quite peculiar since the game continually reinforces how
alien and
unknowable they are.
Beyond the fact that such disjointed behaviour between the two generations supports strongly, a separate faction(hive/collective/group/legion/whatever) theory, it's highly possible that the process they began in the star couldn't be aborted and there was little/notime to move resources through the node considering the fact that jump drives have a recharge rate, the popular theory is that they used the stars drastically altered gravity during it's collapse into a super nova to jump somewhere completely unknown.