Slides don’t need to have bullets. If you do your presentation slides properly, they will be a guide or support to what you are saying. While you can accomplish that with short bullet points on your slides, you will have more impact with graphics and images.
And you don’t need follow the so-called rules of thumbs for the number of slides, since the time you spend on each slide is what should guide you.
Take the slide with five bullets and make five separate slides with either just a graphic that illustrates the point or a graphic and a word or two, but without a bullet point. You can spend the same amount of time on the five separate slides as you would on a single five-bullet slide, yet you will end up with more impactful slides.