M4A4 thing is very disscusable. In theory, playing as CT should be much easier than as T side, becouse you just need to hold angle and it' in T's hand to do the step - peeks, thats why having an one HS kill M4 might be overpowered. In practice we know how it sometimes looks, you are often being peeked by 2 or even 3 guys at once after a flash and probably you are the one holding angle. In this scenarios, if you dont get atleast 2 kills its highly possible round is lost if enemies have utilities, they can use it to literally get on side where is usually max 1 player, especially if you play solo. I think both M4's are at good state, becouse you need to play much more tactical as CT. With 1 HS kill m4, CT side will be overpowered.