Why Vessel Size Mods for attack rolls?

[barsoomcore]

What's the logic in making vessel weapons less accurate if they are mounted in larger vessels? The rules state that Vessel Attack Rolls use the Vessel's Size Modifier, which gets lower and lower for larger sizes. Why do we use this modifier?

I don't understand.

 

[BlackJaw]

I'm tyring to keep vehicles close to the core rules. Larger monsters/creature has problems attacking (penalties to both armor class and attacks) so vehicles have both penalties to attacks and armor class. Basic D20 concept: the larger you are, the harder it is to attack and dodge hits.

balence wise, this keeps vehicles of the same size balenced againts each other. (penalty to attack and AC are the same, so they cancel out) but small fighters can attack larger targets easily and with smaller chances of being hit back. Standard sci-fi concept.

By having both monsters and vehicles follow these same concepts, the two remained better balenced againts each other.

 

[barsoomcore]

Is that the way it works? I thought it was -- wait a second. Ah. Yes, that's right, isn't it?

Okay, got it. Thanks!