I get your point. Unlike nodes in the .dat format, the working of bones is a bit confusing; not always what you see in GR2 Editor or in Goblin is equal to what you see in game.
This is an issue I had reported long ago:
https://www.subsim.com/radioroom/sho...postcount=2259
BTW, the misplaced rudder in stuka's lod model has been fixed by a fellow subsim member:
https://www.subsim.com/radioroom/sho...d.php?t=215466
Maybe you can download his fix and get inspiration from it.
Other than that, my suggestion is that you move rudder's bone in the desired position, and after doing that you re-import its mesh displaced in Blender so that it will show up correctly in game, and hopefully in Goblin Editor as well...
