"[...] we can say that in spite of its multifaceted nature, translation theories can be at least divided roughly into two classes: those which describe either the phenomenon and the mechanics of translation or those which prescribe rules to be followed."
In this sentence, I don't like two things:
1. "its" refers to translation, but a subject of in the following clause is "theories". Is it correct?
2. The use of "either", where the writer used "and" instead of "or". Is it fine?