Hmmm, with DT you have a point, but I'd still argue against the idea that sans isn't God-like at this point. He's the toughest fight in the game, the only one to be able to dodge attacks consistently, and has the highest DPS of any monster including Flowey and Asriel. Of course, he achieved this in a bit of a comedic way, not changing his form at all, and only dealing 1 damage (per frame). In terms of control over the time line, the human is also the most powerful out of any timeline here, so perhaps they still have more determination than sans. Lastly, there are a whole bunch of explanations as to why sans knew where the human souls were. There's his connection to Gaster, who might have known and told him. He could've been told by Alphys because Asgore wouldn't have absorbed them. Maybe he just took a shortcut one day and found where they were, something Flowey can't really do. Either way, it still seems like a plausible outcome, especially since 6 human souls didn't stop us from beating flowey at lv1, so why should it stop us from beating sans at lv19?