Yes. And no, not in correct proper English. I'm not going to say no one would ever say it without "the", but it would be very rare and would be considered casual, non-grammatical English. Even in Klingon conversation, non-grammatical phrases will be uttered sometimes. However, in this course, for the most part, we only accept grammatical Klingon and grammatical English. You can say, "Worf is a skilled officer," or, "Lieutenant Worf is a skilled officer," but if you going to give just the rank and not a name, you must include an article: "The Lieutenant is a skilled officer."