[Alneyan]

I think wormhole damage is applied to the whole fleet, but rather randomly. Fyron had a bit of trouble in Adamant013 with a damaging wormhole that destroyed a whole fleet of ships slightly tougher than scouts.

Some ships can avoid getting damaged, but I suspect the odds are somehow linked to the amount of damage dealt. In any event, it may make sense that small ships might make it through by luck, just like large ships can end up ripped apart (leaky armour would do that).