Every single member of those six races knew that they would have to go to war again. The core of both alliances was the fact that attacking each other would make them weaker when the time for true war came.
Naturally, they shared information with each other. The fire giants and ice giants learned each other's weaknesses but could not take advantage of them.
The two different dragon species were diametrically opposed, but believed that they'd be able to defeat each other no matter the situation if they met again. The Neurics didn't need to learn about the Demons, but they had enough time to gather at least some information.
The Demons did their best to warn the other two races about the Khanii Neurics' might, but they did not listen. Both races were naturally prideful, so they did not take a species that relied on artifacts to fight seriously.
