It would be beneficial for both the system and the user if assets could be assigned to multiple products without requiring multiple uploads of the same file. Similarly, allowing multiple files to be uploaded to a single asset would further optimize efficiency. Both features would help reduce file redundancy and server load.
I like the ability to have a single asset apply to multiple products, but I can't see how multiple files/asset would help.
We run into this with customer envelopes where they have a regular and window version, where the same asset would be appropriate.