I understand where your coming from. I have no idea how Oda would explain how Zoro and Luffy detected more then one person in him, if that is even the case. I think its actually pretty dumb.
But the fact that the scene had the readers pay such close attention to it, I can't just write it off anymore. For years I just couldn't accept Luffy and Zoro just refering to Teach's crew. It has no relevance what so ever in the story, I mean there is no reason at all for that ambiguous dilogue between the Straw Hats. Oda has a tendancy to be extremely CLEAR on what the characters talk about, why would he ever make such a fus about Nami wondering who his crew is?
I think the reason why people weren't discussing it then was because there was no reason to disect it, since it was seemingly obvious. Or in most cases, we all just probably read a really bad translation and just assumed someone messed it up, and cared not to look into it like many other spots in out scanlations.