Exactly. A humanoid robot would have all of the same structural weaknesses that a human would have. You shoot it in the knee joint, now it can't walk correctly. Shoot it in the head where it's "microchip" is, and it will malfunction and shut down. Why even present us with something to fight, besides as a distraction? Maybe send a few hundred larger robots at their target position to get the attention of all the fighters, then detonate a bomb or something containing nanites which enter the human body and shred blood vessels or nerve bundles. People would be dropping left and right, and you'd have no fucking idea why, probably assuming it was a chemical of some kind. There are much more efficient ways at wiping out a population than sending armed ground forces in. Those are only needed if you plan on occupying a territory with potentially hostile civilians/insurgents living there.