A collage looks efficient: a single slot shows several angles or every colour at once. On a marketplace it causes problems. Each picture inside it is small, the thumbnail becomes unreadable, zoom enlarges a grid instead of a product, and a shopper cannot tell which of the items shown is the one for sale.
Rules against collages are usually worded as one product and one view per image, or as a ban on several products or several colour variants in one picture. The gallery is the intended place for more: one image per angle, and one image per colour linked to its variant.
Splitting a collage back into its parts rarely gives usable images, because each part is too small. The better route is to produce every view as an image of its own from the source photos, at full size, and to let the listing's gallery and variant selector do the arranging.