You know, if Marvin Gaye's estate could win their case against Robin Thicke / Pharrell Williams for "Blurred Lines" (they won that? really?? did the judge not have ears???), and now Justin Bieber / Usher are being sued for "Somebody To Love" because it has "the same beat pattern, time signature, and similar chords" as another song ("same / similar"?? really???), I really don't see how Axanar can possibly think they are "different enough" to not be infringing on the Trek copyrights.
Actually, what the Robin Thicke/Pharrell outcome demonstrates to me (though I disagree with the outcome- but I was not consulted; their loss) is that juries are inclined to minimize the "legalistic distinctions" between two works and focus instead on finding similarity when they feel that a defendant is "ripping off" a plaintiff.
Which bodes very poorly for Axanar if their case actually makes it to a jury. I and other lawyers can argue all day long over what is or isn't copyrightable subject matter in Star Trek - but a jury is much more likely to disregard that and say "now, come on - this is a direct ripoff of Star Trek. Anybody can see that." And judges do not overturn jury verdicts lightly.
M