Licence for translations and derivative works

For those who can read French: La licence de « Pepper&Carrot » − Partie 2 : Le choc des licences ?

For those who can’t, in a few words: The P&C licence is permissive while David writes:

Authors of all translations or contributions to this project accept to release this translation work under the license: Creative Commons Attribution 4.0 International (CC BY 4.0).

Whatever you do, you can’t violate the CC-By licence since it is totally permissive.

So I’ve chosen CC BY 4.0 SA for my translation in Esperanto and my derivative episodes because I like this licence. I don’t mind at all if I can’t take part in the P&C project because of my choice.

I just want to point out what to me at least looks like a contradiction in the project’s README.