On the other hand, consider how vaccination was invented or any other "accidental" discovery/invention.
I'm aware that there are inventions that even happen at almost exactly the same time, especially when the research on the subject is ripe enough.
But when chance is a factor or the subject is not researched enough (or at all) then the confidence of an hypothesized invention happening in a close timeframe to the actual invention diminishes greatly.
(The Wrights succeeded arguably because they had the first directed research & development program, while the others basically just bumbled about trying things in a seat-of-the-pants manner. None of them, for example, seem to have done any calculation of how much wing area was needed or how much power was required.)