Merging folders in Sonoma 14.6.1: technical question

I’m trying to understand how the Merge function works.

If I understand correctly, to merge folders on a Mac, you can use the Finder to copy newer files from one folder to another.

The Merge option will only appear if the source folder has files that aren't in the destination folder.

Say I have two folders:

Source Folder:

Apple.txt

Betty.pdf

Celery.txt

Destination Folder:

Apple.txt

Betty.pdf

Celery.txt

Delta.txt

Echo.pdf

According to my understanding above, when I try to merge these folders, I won’t get the “Merge” option since the Source folder doesn’t have files that aren’t in the Destination folder.

But what if the files common to both folders have different modified dates:

Source Folder:

Apple.txt 01/20/2025

Betty.pdf 01/20/2025

Celery.txt 01/20/2025

Destination Folder:

Apple.txt 11/23/2024

Betty.pdf 11/23/2024

Celery.txt 11/23/2024

Delta.txt 11/23/2024

Echo.pdf 11/23/2024

If I try to Merge, I won’t get the option to Merge since the Source doesn’t have files that aren’t in the Destination folder.

But, will the Source Folder files overwrite the Destination Folder files “Apple.txt, Betty.pdf, and Celery.txt” since the Source files are newer than the Destination files?

I am running Sonoma 14.6.1

Thank you!