Last Thursday, Elon Musk made a Tesla Roadster flip and hover, thanks to cold-gas thrusters built by SpaceX. Five days later, on SpaceX’s third-quarter earnings call, he announced that the boards of Tesla and SpaceX are forming special committees to study the possibility of merging the two companies. If you think the timing is a coincidence, I have a Mars condo to sell you.

When I wrote about the Roadster last week, it felt obvious to me that the show was a marketing operation designed to convince shareholders to approve a merger between Musk’s companies. Its job was to make the synergies between his two companies look real. At unveiling, Musk called the Roadster “the culmination of incredible work by Tesla and SpaceX engineers working closely together.”

But that’s not synergy.…