^I'm not at all saying short cranks are wrong, or won't make you more aerodynamic. They can. For the 5'5 woman 170's that came stock on her bike likely are too long. For the right bike/position/person, 155's or shorter may be right. All I'm saying it that people don't understand what is often making them more aerodynamic.
This athlete changed nothing in equipment between these two runs. There is a 15 watt difference between them. That's in the most controlled setting you can have testing differences in aerodynamics.
That's why it's hard to account for "I must be more aerodynamic" because I changed xxx without checking a lot of boxes and making sure you really only changed one thing. In the real world, that means lots of a/b/a/b/a/b testing realistically. (and keeping up with crr drift, temperature, small position changes, etc)
*athlete is me... (~10yr ago)