Uh, that's exactly my point. The Level 5 name on a game's packaging isn't what makes it sell (or not), which is what Y2Kev was implying by drawing conclusions from "no other Level 5 RPG has gotten to 500k". DQ VIII sold (a lot) based on Japanese gamers loving what it was; WKC will sell (not nearly as much) based on how much Japanese gamers like it. Yes, there are contributing factors such as the platform and so on--I said as much in my post--but who coded the thing isn't high on the list.
And who designed it isn't either. Japan loves Yuji Hori games because they're Dragon Quest games, and if he did something else some of that shine might rub off but I bet the fundamental performance would be based on the game itself. Look at what Sakaguchi has managed with his recent games for Mistwalker: some have been very popular for what they were, some haven't.