@tbsprs the 2nd one would remain unchanged.
You need to have something like /res/values-%locale%/%original_file_name% in order folders with languages not being overwritten.
For the 1st one, I’d rather go ahead with simple %locale%, can’t say for sure that the system would work properly with both 2 letters and locale in a folder name %two_letters_code%-%locale%.
For the best experience, I’d advise having only 1 language code pattern per folder step (e.g. per /…/ ) and adding a subfolder for 1st or 2nd translation path, to prevent level-based conflicts (e.g. they shouldn’t be totally the same).
You were granted an additional project for test purposes in past, it’s still (and it will be eternally) up and running, so you can do all necessary tests to check whether the path works properly. Probably better to configure via integration UI because it provides visibility.