Yeah, you can technically get a lot more but it gets kind of ridiculous, like you could technically bring a ghast through a nether portal and line it up as well as a skeleton 50 blocks away to get both sniper duel and uneasy alliance but it'd be quite hard to get that shot.
I just meant like if you shot a crossbow with piercing through several mobs including pillager and phantoms at once to get the crossbow advancement, shooting an arrow advancement, shooting through five mobs advancement and the shooting a pillager with a crossbow advancement. I didn't mean getting all the advancements which i know is already a category.
I was wondering if there was already a speedrun for this but if there isn't I thought it might be an interesting idea, that's about it