In the lawsuit, Jason M. Allen asks a Colorado federal court to reverse the Copyright Office’s decision on his artwork Theatre D’opera Spatialbecause it was an expression of his creativity.
Reuters says the Copyright Office refused to comment on the case while Allen in a statement complains that the office’s decision “put me in a terrible position, with no recourse against others who are blatantly and repeatedly stealing my work.”
I think your approach would not work in practice. The test is not how it plays out when people are cooperating, but what happens when there is a dispute. And if the principle is "providing some input gives ownership" then the photographer, photographer's assistant, agent, employer, and employer's ex-wife will all sue each other over ownership.
In the music industry, you need to actually perform a piece to claim performance credit or specify the verses of a song that you personally wrote to claim writing credit.