The Xperia PRO-I may look like the Xperia 1 III, but there are quite a few internal differences between the pair. However, the more expensive smartphone of the two is also the harder to repair.
https://www.notebookcheck.net/Sony-Xperia-PRO-I-teardown-video-highlights-several-differences-from-the-Xperia-1-III.586328.0.html