I'd think about what and where you photograph. You do have a good bit of overlap with those three lenses. Only you can decide whether or not you will use all the prime lenses. All your lenses are sharp, so that's not really a criteria.
I have the 800mm PF, an older 600 f/4 AFS VR, and replaced the 500mm PF with the 400mm f/4.5. I sold my 200-500 and did not replace it with the 180-600. With this combination I have clear preferences based on location, subject matter, and light level.
The 800mm PF is ideal for small birds. It's also good for hard to approach subjects. It's the long lens of choice when you want reach and the ability to handhold. It's very good to ideal for hiking or outings that require walking a mile or two and longer. The long focal length allows you to approach jumpy subjects without pressing them. I use my 800mm PF weekly for small birds. The one disadvantage is it can be too long at times - especially for large mammals or environmental images.
The 600mm TC is the sharpest and fastest. The integrated TC gives it the reach of the 800mm PF. The faster aperture gives you a shallow DOF and clean backgrounds. But you lack the mobility of the 800mm PF or 600mm PF. The 600mm TC is for situations where a tripod and gimbal can be used - usually near your car or at one location for an extended period. I last used my 600mm f/4 for the solar eclipse, but before that it had been a while.
The 600mm PF solves the size and weight problems of the 600mm TC, but there is a lot of overlap with both alternatives. I'd carry the 800mm PF over the 600mm PF for most subjects. Like the 800mm PF, it can be a bit long at times for some subjects but it's not really long enough for small birds. Given that the lens is not the preferred choice for many subjects if you also have the 800mm, it seems to be the most redundant.
You don't have the 400mm f/4.5. I'd consider it in place of the 600mm PF. It gives you a clearer difference between choosing a long and portable lens. With the 600mm TC and 800mm PF (as well as the 180-600), the 400mm is a light, compact alternative that is extremely flexible and potentially part of a two lens solution. It is possible to carry the 800mm PF in a backpack and the 400mm f/4.5 on your camera. When you need the 800mm PF, you simply put the 400mm in the pack in its place. It's a very comfortable kit. You can also use the 400mm f/4.5 with the 1.4 TC if needed.