[Oni]

Gods among Us and soul caliber are indeed fighters, due to thier core mechanics and design, primarily the smaller stages, 2d perspective, combo based combat system, health bars, power up system, rounds, and 1v1 combat. These are the core components of true fighting games. There may be minor variations, but they generally do not deviate from those basic concepts.

You didn't address how slower gameplay, simpler attacks, or level features would make Smash Bros less of a fighter. I'd say that Smash has smaller stages, a 2d perspective, and a hell of a power up/round system. Ironically, you say these are the core components of fighting games.

Soul Caliber is a difficult one to explain. Its sorta in its own genre.

Also, contradiction.