"We absolutely have no chance of winning if we fight with brute force... To be precise, from the moment they initiated the attack, it was unlikely for us to win."
In reality, reckless war initiators are always a minority. At the very least, they all think they can win before starting a war.
And when these Spider Gods actively attack... the result of their calculations is that their own side has an overwhelming advantage in forces, and they won't even suffer much loss.
But the development of reality has already exceeded their plans.
The products crafted by Healers, Craftsmen, and Scholars began to take effect on the battlefield.
The Invaders brought the "rules" of the Otherworld, which, under the craftsmanship of professionals, became targeted weapons.
And being able to produce the Spider Extermination Divine Artifact in such a short time... we have to thank the generous Money-giving Boy from not long ago.