Greenwood is not one of millions of players out there, his talent is in that bracket I mentioned, at least according to most on here and I tend to agree with it.
I get being inconsistent at 19 here and there, it happens to much older players (also Benzema was the main threat against United in the CL, maybe he was 20 so I was off by one year but all the responsibilities were on him to score and he actually did giving a rough time to Vidic/Ferdinand in a dominated team, also was consistent in the league). Aguero had far more than 5 goals at that age, not sure where you got that, he had 27 goals and 15 assists the season he turned 20. Cristiano was inconsistent but still showed things pretty much every game, I can't remember too many games where he was a passenger the whole time he was on the pitch, which has happened to Greenwood a lot this season.
He's possibly got the highest ceiling of all the forwards on the squad, I don't think it's reasonable to expect him to score or assist every game, but he's been a passenger for most of his games this season but I think it's disingenuous to put him on the pedestal that I believe he belongs on, but then dismiss all criticism of him as irrelevant because of his age, he's not right out of the u-19's.