This is something that all authors struggle with sometimes, because each author has to ask how much punishment their protagonist can handle.
If you are a thriller writer with a super strong good guy surrounded by gunfire sometimes and tough fights… it really makes you think. If a bullet strikes said good guy, your fictive world’s realism comes into question. How bad are his wounds?
Of course this is not only related to physical scars, but emotional ones as well and let us not forget the goals of the character. How much stress can your good guy handle? Is he the only one with these capabilities? If he is no super hero then there are many ways to show that your protagonist is a mortal. I have run into this problem once. I want my protagonist to take part in battles going in guns blazing… but unfortunately bad guys can aim. I agreed and he was shot once, but he is a man and any man will tell you that being shot is no picnic. So I had to think how the wound will affect his movements and such. At first I didn’t and I said to myself, ”Whoa this guy is acting like a tank.” I finally rejected a few gunfights and focused on his strengths. He wound up getting another wound, a stab wound. The fact is my protagonist was destined to be wounded after all the fights he had been in. I have to keep some things real.
Moving on to goals. It feels silly if the whole world has to rely on my main character considering he is a mere man. He has to share some of his objectives. I have no choice. I make him miss shots and I make other characters complete goals. Even though the POV is usually around him… I want to keep things somewhat real. There is tendency among writers to ignore the accomplishments of other characters and what does this do? It makes your hero look like bigger tank.
Few protagonists have the privilege to act like tanks, because most of them aren’t. Most readers enjoy flaws much more. Sure some characters are wounded much more easily than others. Other heroes, though human can take a huge beating. They may also fight well, but I want you to be careful. I know there is a beloved Superman. I also know that he is not the favorite hero out there. If you created a tank you limit the true emotions your character can feel.
”Sure, you are afraid Little Joe, sure the guns scare you… even though you took out a battalion man alone.”
Readers wont buy this. So you, buy this. Get an RPG or a shaped explosive. Destroy the protankanist.