I am by no means an expert on this subject, but I read your post Michael, and I tend to think that there's a flaw in your logic.
You're assuming, or more correctly let me say that I -think- you're assuming, that a given bike will be able to spin the gear reduction necessary to equalize your RPM comparison.
I don't think it is very easy to spin that type of gear reduction... you eat up a lot of energy, right?
I could be way off (I suppose I should go do some research now

), but somehow, someway, I think that the companies building these bikes have already figured out the most advantageous gear ratios, and use them.
I realize the point of your comparison is to 'equalize' the two for purposes of illustration, but relate that to 'as implemented on the bike' for me?
Am I just horribly wrong?... I'm willing to be wrong (and probably am wrong), but at this point, this thing doesn't add up for me. I just want to further this discussion is all, and I'm not picking nits... I really want to know what's up.. tell me what I'm not understanding.
Would it further the cause to just measure the bike's engine output at 1:1? (whatever gear that happens to be??) .. and put big + little sprockets that are as close as possible, and/or account for tire-size diffs by staggering same?
-James