Homecoming and Farther Shore seem separate, in my mind, from the Spirit Walk books as well. Those first two were more of an epilogue for the series vice a new thing. Given the, uh, abrupt way the series ended, those first two books were a way to get a little more of the resolution fans wanted.
Spirit Walk was the first attempt to do something with the crew after that. Which is what my comments were based on. You seem to have left their number of printings out of your math, choosing something more popular
Either way, I don't get a slice of the bottom line, so not really important to me. Creatively, the new VOY direction (and author) work much better for me, whereas under Golden, the series no longer had a reason to exist. Wasn't going anywhere, no mission, just blah.