I used the extractnand tool to extract my save files, then compared to the save files that I had using checkpoint, and was able to then identify that the sword save file will have a file called 'Main'. And using that I was able to then know which game was Sword for me.
You did this for the latest Pokemon? How did you know which save file was Pokemon? I'm struggling to find this lol. I used HacDiskMount to mount the partition and then used the extraction tool on all my save files but none of the files make any sense and I'm not sure how to find the Pokemon one...