So you get to cherry pick over whether its just a nick name but i can't cherry pick over the difference between an arm and a hand?
and no the two are quite different.
Arm:腕
Hand:手
There's no "lost in translation" there
Im not cherry picking. The db says its just a nickname, Gai says its just a nickname. So why should I believe otherwise. I'm saying the writer may not have cared whether he wrote arm or hand, since he's still getting the same message across.
Besides that, I've never ever in my life seen sasuke concentrate chidori in the arm, that doesn't even make sense. If you actually think that makes any sense, then good for you. But whenever I see chidori, it's always the exact same as raikiri.
Here is the story of chidori:
Chidori (千鳥) means "a thousand birds". It's from a story about a sixteenth-century military commander named Tachibana Dousetsu, who owned a sword named the Chidori. One day, he was struck by lightning while sitting under a tree. Acting quickly, he drew his sword and cut the Thunder God riding the lightning. This saved his life and after this incident, he changed the name of his sword from Chidori to Raikiri (雷切, "Lightning Cutter").
Literally all Kakashi did was rename his chidori.