Devotion is fine. It has a long charge up time and its damage per shot is relatively low, it just burns through ammo super fast. Very hard to sustain, which is why you virtually never see anyone using it after the first 3 minutes of a match.
Havoc does feel a bit too powerful right now imo, because it has far less charge up time than devotion, deals high damage per shot and on top of that they gave it the largest magazine of all assault rifles, without even needing to pick up an extended mag for it.
But there's absolutely no "spray and pray". If you want to kill people with these things you have to aim just like with every other weapon. If you're just "spraying" you'll miss most of your shots and deal barely any damage. If anything, because of the charge-up time, these weapons are less noob friendly than others, not more.