Clint Eastwood's poncho aficionado gunslinger is known by at least three different names in the Fistful Of Dollars trilogy, so why is he dubbed "The Man with No Name?" Eastwood was far from the first choice for the lead in The Magnificent Stranger – later retitled A Fistful Of Dollars – with bigger names like Henry Fonda and James Coburn passing. The screenplay already subverted the traditional image of the "heroic" cowboy, with Eastwood's character being shown to shoot first and lie and cheat to achieve his goals.

https://screenrant.com/clint-eastwood-man-with-no-name-joe-explained/