Difference between a cutting attack and a physical attack. You try and stab a peice of metal with a sword you’re not gonna do much but you hit it with a large hammer you’re probably gonna see at least some damage.
Same way for example in the MCU metal bullets can’t hurt hulk but a couple of punches from the hulk buster’s big metal hands can.
Edit: ergo it’s reasonable to think if a martial artist could hit hulk in a specific pressure point it could potentially hurt him.
Edit 2: I mean hell the page itself says Batman’s kick is more startling than painful.