The comparisons between Rooney and Greenwood are off for a number of reasons, with the main one being that Rooney came out of the traps playing in the hardest position on the pitch at 16 and absolutely put the football world on red alert that we were witnessing a potential all-time great turning grown men into fearful statues, non moreso than what he did at the Euros at the age of 18. Rooney wasn't just a talented youngster, he was a player an entire nation pinned their hopes on at 18 years old. He was a player deferred to and seen as the star of an England side with many a great and established name in it. Rooney was being compared to Bobby Charlton, Alfredo Di Stefano and Pele at 18 years old.
There is a chasm between that regard and whatever there is for Greenwood. Goals were not Rooney's only currency in his teams, either, it was the sheer terror he created and exemplified with his overall game, be it running with the ball; running without the ball; passing, or, finally, taking on Roy of the Rovers type shots. Rooney's sphere was encompassing in such a way that the players he was being compared to were all, in their own right known as players barely identifiable and pinnable to a single position on the pitch. Indeed, you'll get #8, #9 and #10 suffixed to the aforementioned, pseudo or otherwise, which was the same thing with Rooney as bombed all over the pitch, but was more associated with coming into his own just past the offensive end of the centre circle. Rooney was already a conduit and a hub his teams went through and was a given to be in the thick of the play throughout a game. Was he erratic? Yes, but at base ends, what was expected of him, which was to be an agent of chaos, he delivered to levels you simply don't see through the centre of the pitch in teenagers but a few times per generation, if you're lucky.
Further to the above, Rooney was also effective out wide even though that wasn't his position or where he even broke through at Everton. If you really think about it, it is absurd what he was and what he was doing at the ages he was doing it at, even moreso than Greenwood.
Greenwood, on the other hand, is a player who is expected to eventually move into the centre and become an out-and-out striker - whether you believe he'll usurp Martial and take the position for himself, it has always been forecast that as soon as his body is strong enough and he's fully adapted to the men's game, that's where he'll be playing (for us or someone else).
On the relative scale, it is easier to start wide and move into the middle of the pitch once mature enough to do so, which is why so many forwards get their break out on a flank instead of through the centre. Greenwood is also finding his feet and the general pacing of the adult game, whereas, even at 16, Rooney had no regard for it, and not just because he was a man-child, but because it was he who was coming into games and setting the pace of them and having those around him play to his beat - something the likes of Maradona did at the same age. It's no slight on Greenwood to say that as overall players at this moment in time, Rooney would be the sun and Greenwood an orbiting planet.
On the other hand, Greenwood has displayed the kind of finishing in his career Rooney could not match even at his peak in the 2010 breakdown season; the kind of finishing associative of very, very few forwards or strikers who have played, which is why the comparative revolve around the same few names in English Premier League parlance because it is such a rare trait. If you read through Greenwood's thread from before or even just as he put his first few goals in, some had already stated his finishing was world class as others rejected the claims as spurious and premature. The issue here is, Greenwood's finishing hasn't deviated since he was in televised games on MUTV, and if you'd been watching him, the only thing that has changed in that regard is the stage he's putting the exact same finishes in the net on. The facts always seemed to be that: if he had a sight of goal, he's going to work the keeper or score; another point evident, and factually proven is the statements about which is his 'best' foot - nothing has changed with him except that he's doing 'it' against pros now and not kids. There's not really a point in their careers where, given the same chance inside the box, Rooney's finishing would be regarded over Greenwood's, but obviously there's a show and prove in that, which trumps postulation. That Rooney striker season, however, where he was heading balls in like the second coming of Sandor Kocsis, there's no evidence to date, that Greenwood can or will match that, but it remains to be seen.
More than his ability to hit the ball with either foot, his ability to hit the ball suddenly with little to no backlift with accuracy and power is what makes Greenwood special. You can, at any time in any era, count the amount of players doing that with frequency on you fingers and toes. These are the players that can beat keepers on their near posts from 20yards out; these are the players who can leave top centrebacks rooted to the spot not even able to set their feet up before the ball is rifled past them. You combine that with being able to do it on either foot and couple it with superfluous dribbling ability, and it means a simple transition from left foot touch to a snapshot on the right, or vice-versa, you have a career weapon that is basically unstoppable until the sudden-burst initial acceleration departs said forward.
There is hardly any means to defend against this action, as even if you know it's coming, the when, the why and the time it takes you to adjust your own shape is an overload that can barely be compensated for. In much the same way as Robben's predictable routine cut inside touches and devestating shot, or Garrincha's standstill to burst cut outside, or Messi's slalom on the left diagonal defined a career, these kind of strikers have the same signature capacity. Robbie Fowler had it, Jimmy Greaves and Denis Law had it, but I think the most famed for sudden strikes from either foot with venom or finesse as required is Romario, who, there was just no way of predicting before he'd actually taken the shot he intended on. Greenwood is of the same ilk as the little Brazilian marvel and has it in him to score the same types of goals for years with little to no counter. It usually at the point when the striker draws his leg back, that the top CB's nip in and block or take it off them; if the leg is not even being half-cocked, you're reduced to a very unique Baresi/Vogts/Chumpitaz/Cannavaro/Cordoba type (very short, fast accelaration and nippy) CB who has it in him to make the challenges in the split-second that will leave bigger guys flummoxed and floundering.
Greenwood is a special talent who is still finding his feet. He has the tools you associate with the best of their time. It wouldn't be a surprise if, injuries and character permitting, he is seen as an absolute superstar by the time he is done. He already has key attributes you cannot find in most of the footballing world, and if he develops the all-round game to utilise those attributes, there's no reason why he cannot challenge the long line of great forwards this club has had to be ranked in the highest tier. It's not a hype job, just simple logic and extrapolation of what you can see.
As an aside, it's a shame how Giuseppe Rossi has been forgotten about in here. He was the most devastating forward who came out of the academy, but his chance to show his wares here were curtailed by what we had up front back then and the status the team had as a whole. Injuries ruined him, but he is a golden boy that shouldn't be forgotten.
so better than the best 18 year old there has ever been then?