but not that weak

Yes, they were, that’s why piracy flourished.

would not have been allowed to stay on the run for long.

You severely overestimate their capabilities. First off, they couldn’t reach the pirate havens. Too weak, as discussed. Secondly, unless the pirate wanted to continued with their infamy, it would be beyond trivial to change your appearance and say you have a different name.

Who’s to say against it? An interpol agent with a photograph of you, demanding you are such and such? Oh, wait…