When Makoa is stunned, aim a bit lower on him to hit his head hitbox. Once you learn the location of his stunned head hitbox you'll see it's very easy to output high damage on him during his being stunned.
Jenos can 1v1 weaker enemies very well, he can pump out some decent damage and then use his Void Grip to allow his teammates to gank you. If you are able to, try to continually shoulder peak him so that he can't Void Grip you, or take a teammate.