There should be a way to customise the order in which the storefront snippet files are loaded.

Currently the snippet files are loaded in a first come first serve principle.

For example like this

vendor/shopware/core
vendor/mycompany/mytheme/
vendor/store.shopware.com/
vendor/mycompany/myplugin/
vendor/store.shopware.com/swaglanguagepack

Loading the snippet files should be like this:
vendor/shopware/core
vendor/store.shopware.com/
vendor/mycompany/myplugin/
vendor/mycompany/mytheme/

So that you can overwrite all others with the snippet files of your own theme.