No, this is your take on the characters. If alignments were being used in the game, Halsin, Karlach, and Minsc would be good, Lae'zel, Astarion, Shadowheart, and Minthara would be evil, and Gale, Wyll, and Jaheira would be neutral (where neutral does NOT conveniently count as good).
So the man who tries to be a hero, if a flawed one, and will under no circumstances be convinced to attack the refugees is ..neutral? Why? His Pact was an act of desperation and a mistake, it does not damn him. He is at heart a good person that has massive flaws. That does not make him evil. Even if you can push his flaws to turn him evil.
Gale.. I have a hard time placing him. So I will not really argue against him being more neutral. (Though he also objects to siding with Minthara).
Jaheira was always Neutral Good. Her being Neutral was a mechanics thing. Harpers are a good organization that want to do good (though I dislike them). *She* wants to do good. She always wanted good actions in BG2 and was against any darker actions.
I am honestly curious why you see Jaheira or Wyll as neutral?
I think the issue is that you are falling into the same trap a lot of others do, which is to see things in a binary way where anyone who is not very explicity evil must then be good, with no meaningful consideration given to what being neutral represents. Simply not going along with evil acts does not make you good-aligned. Ditto for simply "approving" of good acts.
Also, the lore on the Harpers is very clear that they are not considered a truly good organization. They are the classical neutral entity, with a lot of members whose morality is at least very questionable. That's why Khelben Arunsen and Laeral Silverhand were constantly at odds with them, despite their having been instrumental in creating the organization, and why eventually they broke from the Harpers to create a new rival organization, the Silver Stars. The Harpers are very much an "ends justify the means" organization, which is definitely not good. And as for Jaheira specifically, no it wasn't just mechanics. She was very much always on the neutral side, and would simply (and very grumpily) go along with the good acts of a good PC. And from the little I've been able to see of her thus far, she is exactly that way in BG3, an "ends justify the means" character who will work with anyone, evil inclusive, so long as her interests are being served.
As for Wyll, it's a metter of one's perspective about making a pact with a devil. For you, it's a mistake borne of desperation. Fair enough. For me, it's an evil act. So even if it were under desperate circumstances, it fits the "ends justify the means" approach to things. But I am open to the view that he (way more so than SH) is a potentially "redeemable" character. But again I would note, we can here only talk about where each of these characters begins the game, and what their possible alignment is at the point when we first meet them. What happens afterwards entirely depends on the PC's actions, and therefore cannot be discussed in any meaningful way because it will vary from player to player and playthrough to playthrough.
While you make some interesting points, it kind of falls apart for me when you characterize Neutral as ends-justify-means. To me, Neutral is more about not being evil and protecting the innocent only if you feel like it, but Good is just as able to weigh action and consequence as anyone else and to decide whether they can live with a distasteful act that leads to a good consequence. This isn't a philosophical distinction; it is just based on fun. Good characters who must always do the good thing (as judged by the dev or DM) even if the consequence will be greater evil should be given the opportunity to choose instead. It will result in greater character development because they have to choose, followed with consequences of being wrong and all that, such as cynicism, guilt, etc.
It sure seems like Wyll is written to be more good than neutral, all the more edgy because of his patron.
