Trying to understand the sentence
"Which" is a pronoun used to introduce a relative clause and refers most often to things. (Merriam-Webster). In this case, the things are "documents". The verb form to use with the plural noun "documents" is "name". ...the company's most recent documents...which name...
Regarding your second question, the documents name not just one person, but two, as directors: Sir Daniel Bethlehem and Alexander Carp. So the use of the plural "directors" is correct.