Just a possible balance consideration, but light vehicles seem straight up better than static.
Now, I didn't miss that static can be fortified more. But the rules note that chance to hit is the base chance / fortification level, and in the same situation static shouldn't ever have more than twice the fortification of a light vehicle, whereas the base chance to hit the light vehicle is a quarter that of the static. So even assuming a 6 fortification static vs a 3 fortification vehicle, the vehicle has half the chance to be hit. Since it's proportional, this is true even on planets with fortification multipliers (ie on a mountain world it would just be fortification 12 static vs 6 light vehicle, and the vehicle would still have half the chance to be hit).
Unless the base chance to hit and fortification levels are supposed to be one or the other? It would make sense that a vehicle in a bunker couldn't use its speed to avoid fire, after all. I suppose it's also possible that static can use some components vehicles can't, but even in that case it would mean static are only practical when using those specific components.
Seems like the best way to address it might be to make the base size of Static units much lower, perhaps as low as 3. Since the size of the component is added to the unit and determines cost, this would make static units cheaper and easier to transport than light vehicles, but considerably more fragile (especially when not heavily fortified).
With size 3, that would make a static crew served antipersonnel gun size 15 and an equivalent vehicle size 24. All other things (such as armor) being equal, the static would cost 62.5% as much, a given transport could carry 60% more, and both would have the same firepower. However the static would take twice as much damage if both were at maximum fortification or 4x as much damage if they were not fortified at all, which seems a reasonable tradeoff. Or looking at it another way, for equal resources Static guns would have 1.6x the firepower and .8x the resilience at maximum fortification, or 1.6x the firepower and .4x the resilience with no fortification. Statistically, the advantage would get smaller with larger weapons.
At least, if I'm understanding the system right.
Edit: Looking at it I also think light vehicles might be straight up better than normal vehicles, since you're trading a 37.5% lower chance of being hit by every single attack for a 33% higher chance of surviving some hits (hp 4 instead of 3), though that's less clear and there may be other advantages to larger vehicles not clear from the post.