Conventional weapons can reduce hoards to manageable amount. And a zombie dragging itself across the ground is much easier to deal with.

If I saw thousands of zombies, a machine gun is what I want. Aim head at the average head height, and make the barrels smoke. It’s not suppressing fire, it’s crowd management.

Remember you can spike a zombie on the ground easier than when they are standing. Immobilise, THEN neutralise.