If this is a presentation matter then on the frontend this is an advanced customization making multiple collections being presented as one.
For admin sorting there's no simple way to do that as what you describe natively as those tag as are not purely alphabetical or simply numerical.
If products can be retitled adding a prefix may be one approach; keeping in mind the naming convention has to be alphabetical between these subcategories. Note this is different than changing the handle which would affect the url
A workaround may be if these product exist in only one collection to use the product CSV import. But it's been awhile so i'm not sure if the order of products is strictly respected when being added to a collection.
You might be able to lessen the ongoing manual burden by creating a flow in the free shopify-flow app to batch add products you select in the search admin by each tag in sequence.