I also don't know what comics you're reading
Pretty much every Wolverine comic ever published.
but Wolverine makes mince-meat out of "normal" humans.
Which isn't actually relevant to the question, it's about possible impacts, not that he's a better fighter.
Also, there is some flesh and muscle between the metal and skin, so punching him in the gut for example isn't going to result in a broken hand.
Right but there are plenty of examples of people punching or kicking him in the face - Punching normal people in the face results in a broken hand which is why boxers wear gloves - with the right technique, it's fairly easy to break someone's cheekbone but here all you'd done is break your hand and it's rarely shown.