I think
Turin was the mightiest man to feature in
Middle Earth mythology. His whole life was trauma, inflicted by
Melkor (not
Morgoth?). He had probably the hardest upbringing, Plus, entire life of war and strife, developed his fighting prowess beyond that of any other warrior. He was driven by the visceral need for revenge on Morgoth, to make him pay for his sins against his family. So,, physically the strongest ever, the most battle hardened, most skilled in hand to hand combat, and with astral levels of motivation.
From the point of view of the
tales themselves, I think there was a Wagnerian, or Norse element in the mythology, that there had to be a final reckoning,, a final battle to bring closure.
Ragnarok, anyone? Tolkein was highly influenced by Norse mythology, and was it not in the back of his mind there would be the final battle, I believe it;s referred to in Lost Tales or Unfinished tales, when people speculate about the end of days, and the final apocalypse, and the battle between Morgoth and Turin is decided
P.S. I think Turin was the type of guy, if you saw him walking down the street, people would cross over to avoid him