You do not need to make this many galleries.

In fact, the wiki states not to.

"Galleries are capped at 2,000 images.

For works that exceed 2,000 images it is acceptable to create 2+ galleries.
Each gallery besides the last must fully utilize its 2,000 image allotment."

https://ehwiki.org/wiki/Making_Galleries#Limits

Base +42, Joe Bozo +6

Accepted Images: JPG < 20 MB, PNG < 50 MB, GIF < 10 MB. Accepted Archive Formats: RAR, ZIP. Max Resolution: 20000 x 20000.
Max 2,000 files and 10 GB per gallery. You should upload no more than 500MB at a time, less if you have a slow connection.

You should upload no more than 500MB at a time, less if you have a slow connection.

I need to make a rar less than 500MB.

Base +13

thank goodness this is 10 separate galleries then, and theres no way whatsoever to update existing ones to add more pictures to them.

Base +5