I can hypothesize how they'd fare against modern weapons: Poorly.
They're essentially titanic armored fortresses, that would need to be at least 30 to 40 times stronger than high performance concrete just to support their own movement. They’ve fought wars against other giants capable of hurling things like freight ships, and survive that. Within the game context, they’re functionally immortal against humans... until we bring modern weapons into the equation.
Kendra can shrug off RPGs like raindrops, but even she’s going to stop laughing when a 400 m/s
GBU-57A/B Massive Ordinance Penetrator hits her in the eye.
That’s a 13,600 kg (30,000 lb) bunker buster, traveling at supersonic speed, specifically engineered to penetrate over 60 meters of reinforced bunker concrete. Can’t dodge it, and can’t survive a direct hit.
A 60 mm long-rod penetrator (that’s another very pornographic name) is essentially a depleted uranium dart traveling at 1,600 m/s. It’ll go straight through her head. One ear in, the other out, likely bisecting all five neurons that guide her around.
And if nothing else works, it’s time to dust off some
B61 SINGLE TARGET TACTICAL NUCLEAR BOMBS, a $28 million missile that CANNOT be survived if you are made of matter. Directly in her mouth.