Re-using existing assets as "Translations"

I'm investigating the localization (Dimensions/Sets) functionality and are wondering whether it is possible to assign (using Admin Advanced UI) existing assets as Assets Translations.When "Translate" option is selected, the system only allows me to create a new assets.
This is not very good model if we have plenty of dimensions (we need 20+), but most of the content is devided into 3 groups:

So for example I have 3 assets A B C

I have 20+ locales (from 1 to X).

This is the setup I'd like to achieve:

1 – A

2 – A

3 – C

4 – C

5 – B

6 – B

7 – B

etc

Is that possible?
At the moment I can only create 20+ assets for my 20+ Dimensions, but that is hardly effective ...