Originally Posted by
Lauront
It's secondary to what they used to devise Zodiark anyway - which as per the Watcher, is knowledge of the celestial currents, and the entire effort to create and summon Zodiark is credited to multiple scholars. With Zodiark in place they then had plenty of time to develop further understanding of dynamis, potentially better than Hermes's for that matter.
The cutscenes are even worse IMO because they display attitudes at specific points in time where they were still grieving. It wasn't even lack of knowledge she gave up on them over, but their responses to the situation.