I agree it looks bad and irrational. On a level with someone buying wheels for a Y that give away 10 percent of the range.I am aware of the inefficiencies of available wheel choice for the Model Y. I am not aware of significant inefficiencies of the sheet metal design, but I suppose there could be. That would give them a chance to improve.
However, the Model Y has a Cd of 0.23 (coefficient of drag) and the Mach-e has a Cd of 0.3. This contributes to the 30% greater power requirement to maintain 75 mph cruse (paraphrased from Car and Driver coast down test). Therefore, the Mach-e looks stupid.