Heavy weapons were very useful in the present day, it could be said that the one who controlled the largest amount of heavy weapons was the king. After all, the power of heavy machine guns had the ability to pierce the defenses of First Order creatures as long as the soldier managed to hit the enemy correctly.
Taking into account that First Order creatures could still be considered as rarities and at least 80% of the soul evolvers should still be somewhere in the Unclassified rank, the power of heavy firearms was indisputable.
Not to mention the kings of the land, the mighty and almost unbeatable war tanks.
Just the IFV M3 possessed enough power to break the defenses of a Second Order creature that did not specialize in defense. One could imagine then what the mighty war tanks could do; probably even defense-focused Second Order beasts would suffer under the cannons of these ferocious metal beasts that for years were mankind's most powerful mobile land weapon.