Couple of things to note.
Maeve has lead time to hit so playing
Cassie
Drogoz
Shalin
Evie
Imani
Will all help your base aim for leading shots
My opinion Drogoz is the hardest
Dredge can teach you as well if your using left click and not spam reload.
The other thing is Maeve throws two daggers so if you are moving your aim while clicking the mouse your daggers will not land in the same place. This can be used to both degrees of helping and hurting you.
If your trying to hit a fast mover for that final 3oo health then a quick swipe during fire can make your shot pattern much bigger.
If your trying to get max damage down you need to ensure you are aimed and then fire.