But you forget. He said batsy with prep time. With his prep he would find a flaw in chiefs suit and build around exploiting and tricking chief into leaving him self wide open with out realizing it until it's too late. With the aid of his gadgets maneuverability, and skill he would be able to turn chiefs suit against him. Thanks to a recent game theory. We know that the only reason a spartan can even wear one is because of a special neural uplink in the back of his head that let's him directly control the suit instead of using his own muscles. If batman cuts that link chiefs suit would crush him with out batman having to do anything else. Also batman is highly skilled fearless and also has great reflexes.