This is frequently not true. There’s examples all through history of weaker and poorer armies defeating larger ones. From Zulus, to the American Revolution, to the great Emu wars. Surely the birds were not more advanced than men armed with machine guns. But it’s only when the smaller forces can take advantage and leverage what they have better than others. It’s best practices, but what’s best is not universal, it’s best for who, best for when, best for under what circumstances