I haven't really heard anything from Bryan Clark to know what he's like personally, and it's difficult to trust anything the Kliq guys say. All I can say for sure is that Clark was over at the time and Nash's unnecessary squash of him totally wiped out that momentum. Reminds me a bit of the Wardlow situation in AEW, albeit AEW just let Wardlow's momentum peter out, rather than intentionally bury him. I think with Adams and WWE it was just a case of him not being very good, and competition during that period for spots was fierce. WWE was also on a sharp business downturn at the time, and couldn't afford to cater to the whims of wrestlers' friendships - even for someone as influential as Taker. Adams was never going to draw on his own and was a poor worker, so he had very little going for him.
I had totally forgotten about MI Smooth. In fairness to Train nobody was getting over at that time in WCW, so I don't think he stood a chance regardless of the gimmick they gave him. I actually thought Norton suited the role of an nWo heavy/goon perfectly fine. He had an intimidating appearance and a rough looking wrestling style. No charisma or mic skills to speak of, but as a background character who posed a threat he was passable enough. There's only so far you can go with a character like that though, and once the nWo angle began its slow, painful death he was literally just there, doing nothing of note. He was pretty popular in Japan for a while though, so I guess he has that to hang his hat on.
As far as the nWo is concerned - Hogan, Hall, Nash and X-Pac were all solid founder members. DiBiase always felt a bit out of place and was ultimately replaced by Bischoff, whose persona definitely fit into the dynamic better. Giant always felt like a bad fit because they already had Nash in the group playing the role of the big man - there wasn't a need for two of them, and Giant was always better on the WCW side fighting against the nWo. Vincent as an annoying lackey I was okay with, as it's a common trope that you can get some mileage out of, particularly when you need a guy to take a beating without making the others look weak.
Savage I'm so-so on. I think his character did fit the group, but they rushed him into it a bit too early. It devalued him somewhat because Hogan was the main guy, and it made Savage look like a sidekick. I would have been all for Savage joining the group later and then causing fractures with his unstable personality - basically the story they went with in 1998 that led to the split between the B&W and Wolfpac. I think there was some mileage in Savage being Sting's unpredictable ally as the lone wolf for a while at the beginning of 1997, but they had Savage join the nWo before that could ever really develop. With that said, the Savage/DDP stuff was obviously great and made Dallas, so I can't call it a bad booking decision in hindsight.
Bagwell fit into the group like a glove and it definitely enhanced his career, so no issue there. Norton, again, I felt played the role of a low-key enforcer pretty well, so I let that pass. Konnan also seemed to fit into the group pretty well, so no problems there. Big Bubba and Wallstreet, yeah, pointless additions but at least they were kicked out/forced out of the group fairly quickly.
Basically, if the nWo had gone through 1997 as:
Hogan
Hall
Nash
Syxx
Savage
Bischoff
Vincent
Bagwell
Konnan
Norton
I think that's quite fine. In Hogan, Hall, Nash, and Savage you have the star power and all are former popular WWF wrestlers, so it fits into that initial 'invasion' story. Syxx was a worker who could carry matches and had the right personality for the group, so no problem. Vincent playing the role of lackey who can take a beating from the babyfaces works OK. Bischoff as the mouthpiece who wields some corporate power helps make sense of the nWo being able to behave in the way they did on WCW's shows. Bagwell as the young, cocky upstart has a role in the group. Konnan was also quite fresh at the time and could help draw in the hispanic audience, getting the nWo involved in some of the cruiserweight stuff (not much, but still). Norton meanwhile I could take or leave, but in an enforcer type role, he was believeable enough.
DiBiase was really just a placeholder in 1996 until the Bischoff reveal, at which point his role in the group instantly became redundant. Giant I would not have put into the nWo, for reasons described above. Wallstreet and Big Bubba were just making up numbers and had no place in the group. Hennig had the personality to be in the nWo, but just got lost in the shuffle. Rude basically the same. NWO Sting should have been gone for good as soon as the real Sting came out and obliterated him after Fall Brawl. The Nick Patrick, nWo referee stuff was bungled from the start and didn't add anything positive.
So yeah, overall I'd call it a mixed bag. Carefully expanding the nWo was okay, as long as you can give each member a purpose for being in the group. I'd say it was in 1998 when the likes of Brian Adams, Stevie Ray and Ed Leslie came along that the concept became majorly watered down. For the nWo to be a strong force it couldn't just be a handful of wrestlers, as it wouldn't have made sense from a numbers perspective. They needed goons like Bagwell, Norton, Konnan and Vincent to give them some padding and presence as a gang of sorts. All gangs have the people at the top, the people in the middle and the people at the bottom. That's fine.
For what it's worth, they did wash out the members who didn't really fit (Wallstreet, Bubba, Giant, DiBiase) pretty quick and I'd say the nWo of 1997 was overall put together fairly well to tell the stories they wanted to tell. I see 1998 as the year where they really devalued the group, primarily in the B&W camp.