Carrick is the closest comparison that comes to mind.
Having previously looked through some of the posts on here from that time, complaints included things like "what does he do?", "would be fine for £5m but we're massively overpaying", "overpriced because he's English", "not a leader", "Scholes/Carrick midfield isn't balanced", "not a box to box player, which is obviously what we need", etc. And of course people asking why we hadn't signed obviously-better-random-player X instead (I saw Didier Zokora mentioned) or arguing Cartick wasn't even better than Fletcher. One poster even said he wasn't a better actual DM than John O'Shea.
I'd say that the average fan (and so, by default the average forum) gets it right/wrong in the same percentages as clubs' signings are hit/miss.
for every thread of old times that looks funny because top players like Carrick, Vidic, Evra and Ronaldo were given up on,
you're gonna have threads in which Antony, Sancho, Van De Beek, Schneiderlin, Schweinsteiger, Falcao, Fellaini etc were written off from the get-go, and they were indeed car crashes of signings.
Football fans tend to be wildly impatient but they're not always far off in their initial judgement. they're sometimes quite accurate.
All of us posters here have watched thousands of hours of football. While that doesn't qualify us to become managers,
it does make recognizing someone who's out of his depth rather possible.
with Mount, I've no idea what to think.
I haven't watched him enough for Chelsea or England.
And I only saw him in United matches where we were crap so I won't expect him to shine above the collective awfulness.
I'm quite convinced that this Mount-Bruno-Casemiro thing is a really bad idea,
but I can't seem to form an opinion on him as a player just yet.
He's a weird one to digest. Jack of many trades it seems, but master of which exactly?