I’ve created a spreadsheet to compare all the Vinaya’s of all the schools (as far as we have them). You can find it in this repo:
These basically pull the vinaya parallels from the suttacentral api and put them all into one spreadsheet. It does that for each of the pāṭimokkhas we have. For the Pali Bhikkhunī Pāṭimokkha I also added some extra parallels with the Khandhakas.
There are two spreadsheets that you can use:
The various tabs in the spreadsheet each take a base Pāṭimokkha which is then compared with the other texts and parallels in the canon. This base Pāṭimokkha is shown in the first column. Not all Pāṭimokkhas have a tab, only the major ones for which we have a larger amount of data available. Pāṭimokkha fragments of the various schools do not have their own tab for comparison.
and
This spreadsheet shows the same data for only the Bhikkhunī Pāṭimokkhas but with a color coding to show the number of parallels for each rule so it is easy to see which rules only have very few parallels.
I have not made a color coded version for the Bhikkhu Pāṭimokkhas as they are far more consistent thant the Bhikkhunī Pāṭimokkhas. But you can of course download the spreadsheets and reorganize the data in any way that is helpful for you.
The first tab in each spreadsheet has more information on the methodology.