Technically, both pirates and ninjas, as they are depicted in popular folklore, are fictional entities.

We already specified that we aren't talking about the fictional entities. We're talking wikipedia pirates and wikipedia ninjas. That's what you get by default if you taboo 'real'.

Thus, before we can answer your question, we need to nail down exactly what you mean by "pirates" and "ninjas"; what capabilities you expect these fictional combatants to possess, and then go from there.

As far as I'm concerned the question is trivially resolved to an answerable counterfactual, even more trivially answered and in general a solved problem. The whole "spin it into a deep question of ambiguity and definition" is one of the first things I discarded as part of the "ACTUALLY try to answer the question" part daenerys's game under "Being proud of clever retorts, etc."

It is my evaluation that a group who does not execute the reasoning within the minute or so allotted:

• Ninjas vs pirates?
• These guys vs these guys.
• Ninjas
• Next question.

... has simply failed at the rationalist game and requires more practice.