If he doesn't thrive under the pressure of being the main goalscorer of a club like Manchester United aged 18, he isn't good enough? Well, that's where we disagree then. No top club should put that sort of pressure on an 18yr old. Take Barca, Real, Bayern or any other top club for that matter, how many are reliant on an 18yr old to be their main goalscorer? Let's look closer to home, how many of SAFs squads were reliant on a 18yr old in the same way we are on Rashford at the moment?
I am not sure why you are bringing those other players and clubs names? If rashford is good enough to be the main goalscorer, he will become one. If not, he will become whatever he will become. I mean it is that complicated?
If Zlatan comes and plays for a year, and next year after that rashford becomes shit, what would that mean?
SAF actually did play a lot of super talented players around that age. Remember Giggs, Rooney, Ronaldo? And, then again, some would say he should have trusted in that 18 years old midfielder from france and we could have a world class midfielder with us now.
See how it goes? In the end, if a player is good enough to be superstar of a team, he will.
P.S Actually, Martial is expected to win the games by many, not Rashford. It is like some people putting up this agenda to justify their muppet signing in Zlatan.