This is just wrong, you've got it the complete opposite. Literally every player we played on the wing this season was not a proper winger. Martial, Rashford, Lingard, Mikhi and Mata, none of them are true wingers, they all like to either drift inside or cut inside with their dribbling. None of them do any of the the things an out and out winger would do, create width and stretch the defense, beat his man on the outside and play balls in the box.
Perisic would be completely unique in our side and would actually give us some much much needed width. When we play so compact in the middle it's hard to find space, especially as we didn't really have an attacking left back. He's also pretty creative and offers a decent amount of goals and assists. But to say he's just another body is completely missing the point and impact he'd bring tactically