Stuka zu fuss is the ultimate counter to team weapons, because you never can move them in time. What is more, other types of rocket artillery have to shoot at minimal range to be sure they score a wipe against even a single team weapon. Stuka can and will score two at full range, even if your units are spaced out properly just because the line of fire is so long. That makes it the perfect counter to AT guns.
On the other hand mortrars, ISGs and scott can only damage team weapons, but not wipe them, because even if the owner of the weapon reacts after being hit for the first time, he still is going to easily pack up and save the squad. That makes a huge difference for veterancy and manpower cost of being shot at. What is more, the scott can't really engage AT guns, as it will be in their range when firing.
Comparison between Rocket artillery and Scott is misleading, they units work differently.
That is incorrect Scott can barrage ATG from outside the ATGs range. It can even circle strafe an ATG if it is unsupported.
And Scott has a kill radius of 1.27 compared to the 0 kill radius mortars have, it should had probably gotten the same nerf all mortars got.