Assault = AR perks.
Support = LMG perks
Most Assault AR’s are pretty trash currently and are outclassed by most SMGs and most Carbines.
LMGs are okay if you’re running with the Zerg and back of the pack or playing defensively and locking down a street or corridor. Other than that that expect to get beat by everything with a LMG if you’re front lining the push in urban terrain.
The Kord AR is pretty good and the Starter AR is good too. The NVO AR is pretty good as well. But considering most maps are COD boi close quarters with short to medium range engagements, try the Carbines or the MP5 SMG(which beats most ARs up to 50’yards) until the rest of the ARs are made useful and given a propose to exist.