This might need to go to 20, seeing as how a world hater could make 5’s trigger the ability as well, which would end up being a decent percentage of the total hits.
I always assumed that the “2 masts on roll of a 6” ability (and others like it, ex. “double range of cannons but must hit on 6”) only hit on a natural roll of a 6. So regardless of modifiers added. Is this specified in the Code?