Where you are int the order is not a representative of a a PC's power. You can be 3rd best but WAAAAAAAY down in power.
Hawkeye is not as impactful as a 20th level D&D wizard who has Gate, Maze, and Finger of Death.
An Ice devil is a hard fight for a 20th level PC solo. Can Haweye solo an Ice Devil?
This is why many fans use anime and manga as their example of 20th level fighters and monks. Because Anime and manga afford warriors the ability to be as impactful as an archmage. People like Mihawk, Kenshin, and Gourry for fighters or Roshi, Aang, and Jojo for monks would drop CR 14 threats solo (a hard battle for a solo)