I am intrigued that you think those are the problems with the gun.
I would refer to the fact that it has a 3 hit kill at any while being semi auto, while the SCAR exists.
Now, I will say that with a macro clicking left mouse at around 500 RPM (possibly faster, I dont know if the HK has a cap) you can make this gun viable. But realistically, you will not be able to compete in close and medium range situations against a scar.
At ranges beyond 30 meters, it can work out but even then, the scar doesnt have much damage dropoff so it can still easily kill you.