Originality vs. Development in Mexican Standoffs

What's the best Mexican Standoff movie? Leone's original or Corbucci's development?

When I suggested that Ryan Coogler’s Sinners would have worked better without all the vampire/zombie whoop-tee-doo, but instead lead up to a Sergio Leone’s 1966 Good, Bad, and Ugly-style triangular Mexican standoff between the Southern black mobsters who’d stolen Al Capone’s money, the tommy gun-wielding Chicago mobsters come to retrieve their loot, and the Mississippi Delta KKK out to get both, a reader (J.J.S.) pointed out a subsequent Spaghetti Western that ends with a Mexican standoff that I’d never noticed, Sergio Corbucci’s 1968 The Mercenary. (Corbucci, director of the 1966 Django, is a huge hero of Quentin Tarantino.)

First question: Was there ever a triangular Mexican standoff before Leone’s 1966 movie in which Clint Eastwood (the Good), Lee Van Cleef (the Bad), and the Ugly (Eli Wallach) shoot it out in a bullring inexplicably in the American West?

Considering the countless movies made in the second third of the 20th Century, it seems like there almost certainly had to have been.

And yet, my cursory search can’t find one.

Despite the huge star power of Leone’s actors and Ennio Morricone’s famous score, the scene is a little dry and rudimentary.

In contrast, two years later, The Other Sergio (Corbucci) remade Leone’s triangular Mexican Standoff ending with Franco Nero, Jack Palance, and Tony Musante reprising the Eastwood, Van Cleef, and Wallach roles. It’s all way, way more on the nose:

Is Corbucci’s scene a cheesy parody of Leone’s?

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