A layman will say that the introduction of rifles has destroyed grand-army tactics of the past. That is how it looks at face value. Where before, battles would have tens or hundreds of thousands of men, now a single man is able to mow down a dozen in a second. By logical deduction, battles should be smaller. Engagements should not exceed a few hundred men, a single battalion can now cover entire landscapes with careful planning. Through sheer pragmatism and protection of life, armies should now be far smaller than they were in the past.
In reality, the opposite has happened.
