Seems confusing as hell..
Yes. I would forget the ZC vanilla method of organising images: use Image Handler 4.

Your product image url in the csv will be
images/a-sub-directory-you-choose/my_image.jpg

and all the other images you want to show up for that product will be named the same with an underscore then whatever you like.
images/a-sub-directory-you-choose/my_image_whatever.jpg
images/a-sub-directory-you-choose/my_image_whichever.jpg
images/a-sub-directory-you-choose/my_image_whenever_001.jpg
etc....

You upload them all as same hi-res (large) and Image Handler resizes them as needs be, on the fly.