I don't know that I understand. Are you saying that you down-sampled both shots to 1080 pixels on the long side to normalize both formats to the same lower resolution and did the same for the full-resolution crops?
I would expect the results to be very, very close to each other, which they are. As a side effect, there is also a substantial pile of discarded pixels on the floor.*
Steve
* This is always the case for the relatively small images we share on the Web, but even more so when the original had tons of megapickles.