What is the point of Roving Assassin?

Weathered has a Major ID which mostly benefits Shadestepper, but has stats that are in favor of Acrobat.

The Major ID doesn’t even do something that special, it feels like it should be on an armor or something. Getting Health and Mana while in vanish just seems like something that every Shadestepper should have access to.

And the “Roving Assassin” name doesn’t fit anymore, either, because the word roving would imply constant movement, so you’d think it’s an Acrobat Major ID, but no, it’s for Vanish, a non Acrobat ability.

So what’s the point of a major ID being on a weapon that is completely opposite of what it aims to do?

 

The major ID was around way before archetypes were a thing. At the time it fit just fine, but they didn't really change it at all when they introduced archetypes. Specifically, they never adjusted weathered to make it more useful as shadestepper, and didn't change or replace the major ID so that it would work with acrobat.