SMC is incredibly similar to the manga. It is by far the closest adaptation to it. I don't think there's really much to argue there.
I think there can be a broader discussion in terms of 'faithfulness' which is a bit more subjective for each person. For example, it's fascinating to me that fans of the first two seasons claim that Season 3 isn't accurate to the manga and call it an attempt to become the '90s anime, when aside from the '90s homages, that season had the least changes to the manga story and characters. And even with the style change, there are so many recreations of manga panels. On the flip side, Season 3 fans argue that S1/S2 are not faithful to the manga despite the story still being virtually identical... Even some of the changes they didn't like, such as the lack of humor, was brought back in Season 2.
It just goes to show you how many different interpretations the manga has had. Despite it being illustrated, it's still a lot like a textual novel where people have their own 'vision' of the story in their minds. You set the pace with reading it, you fill in the blanks in your head and you essentially direct each scene and how the characters' voices sound. And I don't think any person who is a serious fan of the manga can claim that Crystal played each scene EXACTLY how they imagined it when they first read the comic.
This is part of the reason why there's so many conflicting, even contradictory, reactions towards Crystal, including from super fans of the manga (I'm assuming that blog that was linked is a fan of the manga since they're doing something so tedious comparing each scene panel by panel). Essentially, you're not directly seeing Naoko's vision unfold onscreen, you are watching a director's (whether it's Kon or Sakai) interpretation of Naoko's vision. Quality of the animation, direction and pacing is a huge part of it too, but I think there's a lot to be said about how people interpret the manga and how Crystal matches each person's vision of it. It's a lot more nuanced than just 90s anime fans vs. manga fans which all of these discussions end up boiling down to.