Valheim doesn't have a load order in my experience. It was just plug n play.
[EDITED: Had wrong quote]
Oh, there's always an order. Software parses/iterates one after another. Whatever comes last usually overwrites what came before. As long as they don't step on each other's toes (make changes to the same thing), no problem.
If they do conflict, then you need to figure out which one takes precedence (or which one you *want* to take precedence).
Which apparently Vortex does by filenames(?), since I doubt that it's actually reading the code in the mods to see what is happening.
Which is fine, when you are dealing with files.
But when you are dealing with things that are loading into the game's kernel and changing things, then just looking for filename conflicts won't cut it.
Hence the ancient software troubleshooting technique of disabling something until the problem goes away. (Which can be loads of time-consuming fun with Windows patches...thank god no one pays me to have to do *that* any more.)