to dris
good attempt at justifying your logic.
however, i'm still rather sure that the word itself, "Grande", connotating both the terms 'grand' and 'large/immense' manages to work WHICHEVER way people decide to translate it as. i think of it as meaning 'Great Minus' for Espada members, and 'Big/Huge Minus' for lesser Gillians of larger physical size.
the mangaka's original intent is almost washed by the fact that he designed 'Menos' with small physical frames, (yet huge Reiatsu/power), but the original definition of a Menos Grande does not become any less true. Did any of the Soul Society people even know of the existance of Espade type Hollows before learning from Aizen's Arrancar? If so, it makes sense that the term 'Menos Grande' could simply be decoded to signifying 'A big/nasty Hollow', as far as SS is concerned, capturing the giant Gillians and the compact Espada.
that's why semantics is an art and not a science.