You're right, it wasn't Cruzz. It was a conversation with yourself. Here is what you concluded after a few of us did tests.
"I think you have a point, and that was a mechanic I was not aware of beforehand.
Rifles and LMGs have the "focus_fire" property on, which I assume is what turns singular LMGs into death-ray-laz0r beams.
However, SMGs/assault rifles don't have this property on. This is probably why, even though the affected units deal a ton of DPS, they don't immediately snipe models. I have no idea, however, how the damage is spread (do they affect multiple targets within the same burst or not)."
So as I said, dps does not always translate to statistically higher chance of winning an engagement. In this case the kar98 drops more models at long range and so is the more deadly weapon at that range.
I was wrong back then. I did some testing about that a few weeks ago:
I was running a test: vanilla Volksgrenadier squads with STGs (focus fire off) vs Volksgrenadier squads with STGs with focus fire on. The vanilla Volksgrenadier squads won every single time.
Then, when I moved to 1-model vs 1-mode, focus fire did not seem to have any effect. Thus, it's as Cruzz described: The focus fire attribute for which STGs benefit from actually adds extra damage; it doesn't disperse existing damage.
Do we know how much does this shots may scatter? I guess this can be done by testing it against Falls (which i guess they are one of the units which hug the most) or spawning several 1 model squads and putting them side by side.
I've never tested this enough to find the exact contribution of DPS.
According to the description, the new target has to be in the scatter area of the shot (which is usually pretty long but narrow). The description also hints at a new accuracy roll, which would be pretty significant.
However, I don't know if scatter-hit candidates can involve entities other than soldier models (e.g., sandbags/fences), etc.