Also, your ideas of "importance" are fundamentally kind of weird. You talk about these characters being higher ranked than final/extra bosses with plot importance like Suwako, but how is Suwako any more important than Koishi, Mokou, and Flandre, who are all also Extra bosses? Like, what exactly was the criteria for this supposed to be? I mean, some Extra bosses are generally important to the series, like Mamizou, but that's clearly not what you were talking about since you wouldn't know that.
And while you clearly love Satori, how is she more "important" than Koishi? Assuming you pretended the fighting games didn't exist, both of them are sisters who only show up in one shooting game. Their backstories are explained entirely in the manual, and they don't get all that much dialog each. Heck, what makes Satori more important than Parsee? Stage position? Being nominally the ruler of a place? Satori served no particular role in the plot of SA, other than being someone Orin was afraid of. Frankly, her popularity is far more surprising than Koishi's, because she's basically never shown up again in canon (she made a brief cameo in SA, and probably got as much dialog in Koishi's ULiL ending as she did in SA).
Same with Sagume. Sagume's actually quite similar to Satori, in that she's a stage 4 boss that's nominally in charge of a place. She's slightly more important though in that she actually does something related to the plot of the game. While it is unusual for a new character to rank so highly (ironically this is because of all the fanwork momentum the older characters have: if we were judging strictly based off the games in a vacuum I doubt Remilia or Alice or everyone else would place quite so highly compared to Miko and Byakuren, etc), Sagume ended up right next to Kokoro, who was another breakout modern character. So it's clearly not unheard of. So why shouldn't Sagume, who has a cool design, a cool power, and an interesting personality be able to compete with Satori, fair and square? What, other than the aforementioned fandom momentum which is exactly what you're complaining about, should make Satori an objectively more deserving character than a newcomer? I mean, tastes are subjective so there's nothing wrong with Satori being in the top 10, but by the same logic there's nothing wrong with Sagume making #14 either. People like Sagume. Heck, I like her.
Popularity poll are just popularity polls.
