How do I batch-change people name on multiple images?

I am blessed with two sons which the photos app is not able to properly distinct as two different persons and I am ending up with:

• several thousand images to be tagged manually
• lots of the images assigned by photos to the wrong person

1. Is there any way to batch-replace the person label "sonshine 1" with the "sonshine 2" in a selection of multiple images?
2. Some of their baby pics are difficult to distinguish even for myself, I have to peek at the foto's date. Using the "confirm additional Fotos" doesn't show the date / info of the photo to facilitate this.  Am I missing something and / or is there a workaround for this?

Thanks in advance for your tips :)