Re: Firearms in fantasy?
That cossack is a great find. Repped.
ISTR that the earliest bayonets were essentially big knives with handles that could be jammed into the end of one's musket barrel, turning it into a makeshift pike. Swords as backup weapons makes sense, both militarily and otherwise, as hunters/soldiers without the luxury of reloading before the boar/enemy soldier charges will have to use something lethal very quickly if they want to remain alive and unharmed.
If you rule that firearms are "armor-piercing" (however you define it) against normal armor, it should also be armor piercing against normal animals with "natural armor". Dragons and the like might be exempt, so you might want to reconsider sending the musketeers without a lot of extra soldiers, some sort of anti-dragon magic, or a(n extremely) clever plan.