For the stats inclined, and do feel free to skip over this post if the word stats just made you involuntarily shout 'utter woke nonsense' over your cornflakes...
He's played enough now for there to be some data available, here's the link for him this Championship season:
Compare Harrison Armstrong to others in passing, goal scoring, attacking, defense and more for the 2025-2026 Championship
fbref.com
Main caveat: 500 minutes is still an extremely small sample size
Headline info: pretty incredible for an 18 year old in his first ~6 games at a new club.
One important thing to bear in mind when reading it is his touches and passes received are pretty low. Sometimes that means a player is poor at being in the right place at the last time and games can pass them by, which is common with young players, but in this instance it's more likely a function of the team he's playing in and style of play - all their midfielders do. In any case, it's something you can fairly confidently say both elsewhere and as he gets older.
This means a lot of his numbers will be fairly heavily suppressed by simply not being on the ball as much. But! And this is a huge but! He still has REALLY GOOD numbers in lots of areas. That's incredible again considering his age and being new in a team. On-ball things that really stand out to me:
Progressive carries
Carries into final third
Progressive passes
Passes into penalty area
These are all above average, some of them enormously so. When you adjust for the amount of touches he has, you're talking stratospheric in some of them. A great comparison is Wharton's championship season at the same age - adjusted for touches, Armstrong is slightly below in his passing forwards but WAY ahead in his carrying. These are some of the kind of stats I look at first for midfielders because it basically says: how good are they at moving the ball up the pitch and getting attacks going?
Some defensive things that stand out - he wins a stonking amount of things in the air, and is extremely hard to dribble past.
He's mentioned that Moyes has tasked him with adding more goals and assists and that's understandable because he's currently not affecting things around goal much at all.
Anyway, it'll be interesting to see how this develops over the season, and I'll be particularly fascinated to see if he manages to get on the ball more as perhaps his teammates start looking for him, and he starts really controlling games. But this is a profile of a kid who is looking to do something positive with the ball a staggering amount of the times he gets it, and often succeeding. He's looking real good.