Depends how you look at it each of them is capable of getting to 20 in all comps add Bruno to that 15-20 that's a lot of goals before you start thinking what others can add.
It obviously assumes the best in terms of development but you would imagine the club see those 3 as a potential forward line that could compete with anyone else in the world. There also needs to be co-operation between them my only issue with Rashford and Greenwood is they can be a bit of the playground ball hog head down trying to beat 2 or 3 men rather than look to work together to play a passing move that could open up the chance.
Those two need to learn to be creators as well as scorers which is what I'm hoping Sancho brings to the table.