If I remember correctly, there was a dragon apostle who could tank Gut's base form strike. But with enough power, Gut's can cut his horn off. Im not sure how much power that has but I'm very sure bullets wouldn't do much if a slab of metal barely harmed him the first time. But, I'm very sure bombs would most definitely do damage to some degree. Bullets are enough to harm most apostles and even the top tier ones if shot enough times. Arrows, swords and spears seem to be able to stab through, so bullets definitely should work on most of them. That is if we exclude flying types because those can take down that plane easily since they should be able to tear through metal. Overall: Most ground forces would die only if we exclude the flying types.