As with many things, it is best to "have your bases covered" should a question arise. For example, I take three medications for hypertension. I could probably make my packing easier and just dump a few days worth of pills into one bottle or baggie and get through a cruise with nobody saying anything. But then what happens when I get randomly picked by Customs for a bag check? "Sir, what are all these pills in this baggie?" So I follow the TSA rules and bring all prescription drugs in their labeled bottles.
Our members and moderators have years of cruising experience. Some are cruise specialist agents who hold difficult-to-achieve accreditations and certifications. If they suggest you do something you can bet it is based on an actual event that happened to one of their clients in the past, or on information they have received from the cruise lines, or from their experience over the years.