Its hard to say whether an acquisition of SPE would get approved. If it was just SPE on its own maybe. SPE on its own would be on the level of Marvel or Lucasfilm imo. If it was just the Spider-Man rights they really wanted maybe they could enter an agreement with the DOJ to spin-off SPE after 90 days once they transfer the Spider-Man rights to Marvel. It seems like whole lot of work to go through the approval process just for Spider-Man though.
I still think Disney entering into a partnership to acquire SPE with a Amazon or Netflix isn't a terrible idea. I wonder if the DOJ would allow it if they said "All right tbh we really just want Spider-Man, Sony has agreed to sell, once we give Spider-Man back to Marvel. 90 days after closing the acquisition we will spin-off SPE to our partner Amazon/Netflix"
I think it would be easier just to have Amazon/Netflix buy Sony and then just have them sell Spider-Man back to Disney as a way to get back some of their money. I would think it would also make it so that the DOJ doesn't need to get involved. If Disney is the one to buy Sony and then spin it off I would also like them to keep Men in Black (Marvel owned property) and Ghostbusters (just want it out of Sony executive hands).