Is it permissible to perform Friday prayer behind imams who are not proficient in reciting the the Qur’an and whose sermons are delivered in an incomprehensible language, while there is someone more worthy of leading the prayer?

It is not prescribed to have more than two adhans on Friday. The khutbah (definition) (sermon) is only valid in Arabic if someone capable of delivering it in Arabic is present. Otherwise, there is no harm in a non-Arabic khutbah. As for the Imam's recitation, if his mispronunciation alters the meaning, then prayer behind him is invalid. If it does not alter the meaning, then it is valid. You must perform Jumu'ah prayer with them unless there is something that invalidates the prayer; otherwise, you pray Dhuhr.