Actually, a properly scaling explosive effect might be better (more flexible, anyway) than directly scaling projectiles based on damage or group size. This way we could still engineer gauss cannon style weapons that rip holes right through a ship even several hundred meters long, or take the same weapon, add 75% explosive and see a larger projectile that hits with a 5 or 10 meter radius of damage in exchange for reduced penetration. Basically what it seems like Schine wants to do with explosive anyway. Some very small degree of scaling from size/dmg could be OK too, but they'd have to keep it super small otherwise people will go put 100,000 cannon modules on their ship for a projectile with a radius of like 50m or something.
Which I guess would be fine as well if projectile speed scaled inversely with size. Otherwise it (further) nerfs maneuver as defense and (further) pushes the playable meta towards the extreme size end of the scale. Because dodging a bunch of 100M wide cannon rounds flying around at normal cannon speed would be impossible. They'd be like projectile flyswatters.