GobHag
Adventurer
It's not muddying up anything.
These terms (Supernatural, Transmundane, Magic) all amount to the same thing in 5.0/5.5. The system is not nearly granular enough.
If we were talking about PF1, we could have a debate about this, and 4e, but thats not the reality of the world we live in.
5.0 is (unsatisfying for both sides!) the 'lets try and just appease everyone a little' edition, but if its not actually mundane, blood and sinews, then it is in fact, some kind of magical/fantastical/whatever.
In no world is a javelin toss of 1600 meters, anything but magic.
A javelin throw in general is magic, I mean a bunch of wet strings pulling on living rocks to throw a sharp piece of metal? Magic!