I agree that Leao might be a better option for Manchester United than Lookman. The two are good players but Leao proved himself in AC Milan many times and could adapt perfectly. I have some worries that Lookman will be the new Victor Osimhen, he needs to learn from his Nigerian teammate who was once, one of the best players in a season then he faded.
Why are you comparing the both players when they play differently and play for different teams at the club level. And even when they play in the national team, everyone does their job perfectly well. It doesn’t mean what happened to Osimehn will also happen to him. Lookman is a great player and not has he only proved it last season but also on the verge of it also this season. If given the opportunity to play for Manchester United, I am sure he will do well just like I also believe in Leao to be a good player for Manchester United when he’s signed. They play from same position and if they pick any of them will really help them in the forward position, I don’t see anything wrong in any of this two players if they want to go for them.