Actually, that's a rather good analogy. Imagine a fight where you're against an opponent, and you both have shitty starting spear units.
If you have 1 unit of each, well, have fun and be sure to get a good charge off, I guess, either way, they're going to duke it out, and no matter what, the results will be pretty 50/50
Make it 3 vs 3, and you can start flanking, or maybe even getting rear-charges, and these will cause the enemy to quickly lose a multi-front fight, lose moral due to being surrounded, and you'll quickly grind them up and rout them. But if you march in head-on, its going to be another long grind that could go either way.
But, if I have even just 1 war elephant, and you just have a few spears, I can just steamroll over all of you. I don't care if you get a full surround, even, I will kill all of you, and there is very little you can do about it, tactics be damned.
Or if we both have three units of berserkers, they won't listen to orders properly anyway, and they're best just running headlong into the fray to make use of their massive charge bonus, so we'll likely resort back to just smashing lines of them into each other, and maybe try to wrap around the sides, at best. It just doesn't matter as much, charging straight into them works almost exactly as well as delicately positioning them, while taking way less time and micro; why bother doing anything but charge?