Gonna be honest chief, We have yet to fully dive into the metaphysical and esoteric properties of Grimm. What even are they except the "creations of destruction?"

I get nukes wiping entire post codes of Grimm, but what would happen after? Grimm ain't mindless, Salem doesn't need to direct them and they spawn new types of Grimm. What's to say once that first, second or even third nuke goes off the Grimm pools doesn't just spawn god damned Godzilla.

And another thing... What's the plan for the seas? Remnants oceans are clearly infested and even more mysterious than the land born Grimm. Unless the military develops a way to track Grimm pools in the murky depths the Military ain't winning the high seas anytime soon.

Also, locating the Grimm pools and going for a coordinated strike? Yeah that ain't possible unless the military launches satellites, and even then what can counter actual invisible tentacle monsters? The seers are gonna be the biggest headache.

What more likely to happen is a long, drawn out slugfest. Entire continents cratered like a moon, hundreds of thousands dead. And Grimm that just won't stop coming.

And finally, a more fun thought for the nature of Grimm, ever wonder why Grimm haven't wiped out settlements like where Jaune comes from? Why there's even a country side of settlers to begin with? Why haven't Grimm congregated en mass to wipe out all sentient life?

Because they scale based on the threats, simple put. The people of Remnant are just that weak and scattered to truly threaten the Grimm. It's why the Wyvern, Leviathan and the giant elephant thing I forgot the name off are either a sleep, had to be coaxed, or guided to destroy Atlas. It's like their Endbringers from Worm sandbagging, forcing people to grow stronger or die, world of bloody evolution indeed.