There is one plot point most Legion fans will loathe--but that could be explained away by the fact that the questionable character already has an established weak-willed doppleganger...
Indeed, your referenced plot point was among my main gripes, but thanks for pointing this out, I forgot about the "weak-willed doppleganger", good way to rationalize it.
It doesn't upset me quite as much because I very much doubt his version of Legion will be continued (though watch this be the time if finally is...), but then that is not a good sign..
So overall, while I enjoyed watching this, I was disappointed versus what I hoped for . The main reasons being:
--- 1) both the above-referenced plot-point, plus other characterization inconsistencies (Dawnstar has been portrayed in many iterations in a reasonably consistent manner as a regal and dignified persona, here she is the opposite) made this all feel "too different" from any canonical representation of LSH.
--- 2) similarly, the near flip-flop of Legion seniority - Phantom Girl, Chuck, and Triplicate girl as academy recruits, as opposed to being among the most senor members in the comic, whereas we see Power Boy as a full legionnaire in a latter group shot - made this fell like a weird "twilight zone" version of teh Legin (I like Eryk Davis Ester's "ChatGPT" analogy above.)
Exacerbating this is that despite several group shots, I couldn't find key Legionnaires (Star Boy, Sun Boy... someone said they saw Element Lad, I only think I MIGHT have seen him...), while others in the shot were never even members.
---- 3) Arm Fall-off Boy - I love him as pure comic relief, awkward to make him part of the action and a legitimate contributor - takes away any real drama.
---- 4) The title is "Legion of Super-heroes", but the only characters who were at all developed were Supergirl and Braniac 5, the rest were largely bystanders. 20th century Justice Leaguers and Kara's own mother got more attention than any Legionnaire.
Usually, with little to no Legion out there anymore, I root for any incarnation to succeed, but this is one of the few that I hope will not continue (and i guess I am "glad" that I doubt it will).
It was still enjoyable to see LSHers in action, and I suppose if it DID continue with more focus on the main team, I might change my mind (esp. if they "fix" issue #1 via the doppleganger), but as it is now, this would rank near last among many recent versions of LSH that have popped up randomly (including the appearances in the last season of "Young Justice")
But to be fair, if otherwise ignored characters are your favorites, I could see being excited by this version "mixing it up" versus the standard "canonical" LSHers. I myself did enjoy Chemical King's primary role, for example (although it took me some time to identify him, at first I thought he was ME lad. (Is it a tooth? No, it's a beaker.
),
So as is almost always the case, "better than i would have feared, not as good as i would have hoped", but this one was a bit heavier on the "not as good as i would have hoped" than other recent efforts. for example, I watched this with my son and right afterward, we watched "Justice Leagus vs. Fatal Five" on HBOMax... SO much better! The point being this latest effort, while definitely better than nothing, ranks near the bottom for me amongst other recent LSH incarnations.