For the critical hits, yes. It was an abstraction of the “damage to all creatures in a 5’ line” for the ballista and “damage to all creatures in a 5’ area” for the onager, but I didn’t define it thoroughly.
I’m also glad to see that the ranges mostly worked out. I wanted to have S/M/L so that they could be treated similarly to individual ranged weapons. The onager probably is a little bit long-ranged, but I haven’t had a chance to see how the combination of long range and poor accuracy (-6 at 21-40 hexes) actually works out.
New rule:
Initiative: Ships move on their captain’s initiative, with a +1 bonus for each time the captain has taken the Seafaring proficiency. Marines and weapon crews act on a separate initiative roll, with a bonus if the leader of the marines has ranks in Martial Strategy. (Note: if a campaign will focus on both sea and land battles, a Naval Strategy proficiency that functions identically to Martial Strategy but with MS specific to land and NS specific to sea may be prudent)
Clarification on firing arcs: broadside weapons may trace their line of fire from any hex that the ship occupies. F, FP, FS, and FT weapons trace line of fire from the front hex, while A, AP, AS, and AT weapons trace line of fire from the rear hex.
Topic for discussion: I am considering having a rammed ship forfeit its next movement and take a penalty to shots for one round to reflect the ship being shaken up. This would tie in to fleet rules, where initiative determines who moves first, with each “class” of ship moving before heavier ships, letting the light ships try to disrupt heavier ships by ramming.