Huh???
Are you talking about starting a fight with Sargos in New Garand? Yeah, that's a tough fight. Not impossible, but very unlikely when you first meet him. The game design is for you to agree to meet him elsewhere. The combat option just teaches some humility.
Beating Sargos in the arena is a routine part of the game.
Side-stepping the alien-centric nature of your comment, did you ever stop to wonder if Sargos himself is alien, or part alien? There are lots of aliens running around. Some are known wizards and sages, some are known criminals. It's well within the game lore to speculate that Sargos and other seemingly superhuman figures are in fact superhuman.