The final build I'm suggesting for Champion status is a fun Dakka build, with
2 UAC2s and 3 ERSLs.
This build presents the experience of ballistics on a mech, and it can be effective at almost any range. If the fight lasts long enough and the ammo runs out, there are always 3 ERSL to continue the fight with. Even then, it can easily handle the heat of both the UACs and the lasers shooting at the same time if a target is close enough for them to hit. The lasers also come in handy if the UACs jam when up close in a desperate fight.
I've personally had a lot of fun with this build, and it's become my default Adder to play with now. My only concern is how well UACs and new players would mesh, but I imagine it would be effective still as long as they are throwing lead down the lane. And with UAC2s streaming the firepower, they can "tracer round" their shots into their target, making corrections to aiming easier.