Abraham is still a bit lanky as well, when he fills out a bit he will add some strength to his game that I can't see Rashford reaching.
Rashford has been doing it at a higher level though.

Marcus-Rashford-Premier-League-2016-17_jan6_radar.jpg
Tammy-Abraham-Championship-2016-17_jan6_radar.jpgKelechi-Iheanacho-Premier-League-2016-17_radarjan6.jpg

Rumours are Kelechi is going to be sold in the summer to a bundersliga team, but with buy back clauses.