Originally Posted by MarkL
Do I have it right? Are KMM and TSLpatcher two ways to do the same thing? Do I need both? What does one do that the other does not? Any insight appreciated!
Not quite, KMM and TSLPatcher serve two different functions. As far as I am aware KMM is a mod manager meant to be used by the mod user to easily turn on/off mods in their game.
TSLPatcher on the other hand is mostly a mod-makers tool to configure and ship with a mod when uploading it to allow easier compatibility with some other types of mods. It acts like a mod installer that modifies files like dialog.tlk, 2DAs, GFFs, ERF/RIM files etc instead of overwriting them in an attempt to allow different mods modifying the same files (but not same same set of data within them) to coexist. In simpler terms it allows the mod maker to handle most of the hazzle of mod compatibility so the mod user won't have to merge files by hand. It's only useful or practical for certain types of mods though.
So in short you'll only need KMM of the two. If you make your own mods you may or may not find TSLPatcher useful as well, but it's not something you need to get just to use mods others have made.