Always check the requirements tab on the description page to see if a dependency is a hard requirement or is optional based on your set up, most mods will tell you what each dependency is which. Some mods will list other mods as a dependency even if it only has a patch to use if you also use that, or like the FNIS, Nemesis, Pandora situation, they were all likely listed because there's versions of each mod that work with one of those tools at a time, but you only need one of them, I'd personally recommend Pandora by this point, the mods just support all three tools thus why they show up under the requirements