Show me in the manga where it's said Luffy is not a human being. Luffy has a description of a human being physically. Done it's easily refuted.
The description of someone who uses all of his haki is not someone who says he keeps exuding his haki because the description of someone who exudes his haki is someone who pours some of his haki not ALL of his haki.
Now show me where is it said at this level refers to Zoro poured all of his haki which fits this description. I'm holding you accountable to your statement. Don't run away.