Again, why randomize spread?
Make it predictable but constant deviation based on hardpoints and location. The point is all the damage doesn't go to a single point at the click of a button.
Let's take this fine looking
Centurion. His hardpoints as shown form a vertical line, both in the right arm and left torso.
His right arm has three hardpoints (for this, let's say it's a triple AC/2 build). They fire a bit right of center on the arm crosshair. The top AC mount fires a bit high and right, the middle hardpoint straight but still a bit to the right of crosshair, the third hardpoint a bit low and to the right of crosshair. The arm mounted guns will spread hit in a vertical 1-2-3 line that spreads out with distance. If he brings his arm gradually up and fires 1-2-3, he'll even be able put all three shots into the same spot.
His left torso has three SRM launchers. They fire a bit left of center on the torso crosshair. The top SRM rack fires a bit left and up, the center one straight but a bit left, the bottom one a bit low and left of crosshair. Again, it's a vertical spread- SRMs will not only do their usual spread, but also impact high/middle/low. Again, he can bring his crosshairs up and fire his launchers in order to put them into the same spot. Spread on an alpha is predictable, but hardpoint spread can be prevented by shifting the crosshairs after each shot to get them into the same location. This prevents alphas from automatically getting a zero-spread hit.
If he had a
Centurion with the dual CT energy hardpoints, they'd fire a bit high of center and a bit low of center if he mounted a pair of lasers. Again, you'd be able to put the crosshair on target, but all weapons wouldn't instantly be able to hit the same precise point. You could even cycle your weapons to do it, shifting your crosshairs to compensate as you fired each weapon in turn and knowing exactly where each gun was going to hit relative to the crosshairs.
You just couldn't fire all of them at once and have every weapon hit the same spot, you'd have to aim them in a predictable pattern of sequenced fire. Fire in bulk and your guns can't all compensate to hit the same spot. Lots of damage quick, but spread further across the target.
Fire in sequence? Less damage at once, but you can place that damage more accurately. Aim will matter.