Scenario: Humanity is given 6 weeks awareness prior to E day.
The locusts were firmly applying belt in the first day of emergence and up until the hammer strikes. Humanity after 80 long years, had entered a peacetime era before finally succumbing to war again.
Let's look at the facts for a second. If you read the rise of Raam comments, Raam is fully aware that Locust will go extinct against the Lambant threat and that by Scourge's vision, the horde will fall in their effort against the surface dwellers (us). The war against humanity was never a won war in their imagination, as so much as it was buying even more time.
Okay, let's look at another fact. It took just a few lightmass bombs tucked into the outer hollow to utterly eradicate the locust population. This was the end of gears 1.
Now let's talk. From what I gather, the locust numbered a few million at the start of E day. Humanity was at 25 billion. I want to begin by saying that I don't believe these numbers make sense even with the element of surprise and having brumaks run rampant. I don't think the locusts should have won out simply because weapons of mass destruction exist. But anyway. Let's say humanity has a heads up. Let's say they're aware of an emerging threat and having information symmetry. They know of corpsers, of brumaks, of the kryll. Here's my take. Humanity installs ALOT of hammer of dawn satellites. Ramps up production of lightmass bombs. Begins a militaristic, planet-wide coalition that arms every fighting man to tooth and nail. With a strategic coordination, I don't just think humanity would win the war, but they'd utterly eradicate the locust before E day can even commence. Mind you, a single / few lightmass bombs eradicated the entirety of the outer hollows. The sinking of Jacinto further brought the locust closer to extinction. The trouble was in finding their home world, at which point even a crippled 99% extinct humanity force could still rid of the locust threat.
That's all I have to say. And I sincerely hope e day comes out next month!