Your sentences are understandable, but there are some mistakes. Regarding “workforce,” that word already means “a group of people [who work],” so you don’t need to say “ a group of people” in your sentence. You could just write: “A healthy workforce is generally productive.” Your second sentence is incomplete. When you start a sentence with “because,” there have to be two clauses in the sentence. The form is usually “Because [clause 1], [clause 2].” Examples: Because he is tall, he can reach the top shelf. Because she is beautiful, men want to talk to her.