Lee, while that second list is closer, it's still off.
I say that with a grain of salt because it really all depends on what you want to use as your starting point. The "magic number" you were trying to determine before is 1610. That is based on the average height of a male to eye-level being 5' 3", which translates to an overall average height of 5'8" or there abouts.
Yes, sounds short by today's standards, but remember this "scale" is supposed to fit everything from an ancient greek warrior (and those dudes were short back then) to modern man. Nobody cares that the average height of a greek male was 5'3", when you buy a 28mm figure, be it an ancient greek, or a figure of Napoleon, or a figure of Monty, you expect the figure to be about 28mm tall. Thus, the standard was set long ago to be 5'3" to eye level.
Also, something to consider is that while people can vary in height, thus making any scale based on a person both right and wrong depending on who you ask, certain man-made elements remain true regardless. This is where the railroad industry (and thus model railroaders) helps anchor scales for us wargamers. Because the tracks of a certain type of real-world railroad are ALWAYS the same set distance apart. And long ago, for whatever reason, they decided to make "this" gauge railroad track only "x" mm apart, and "that" gauge "y" mm apart.
Thus, those scales are absolutes in the real worl. For gamers this means:
N Scale = 1/160 (or 10.06mm)
HO Scale = 1/87 (or 18.5mm)
OO Scale = 1/76 (or 21.2mm)
S Scale = 1/64 (or 25mm)
All of those were to eye-level, so you can tack on a little bit more to reach top of the figure sizes.
So, take the magic number and divide by ratio scale to determine the mm scale, or divide it by the mm scale to get the ratio.
Since Mongoose has posted their ratio scale, you can easily determine what mm scale that is supposed to be. They say 1/65, so 1610 /65 = 24.76. Remember that is to eye-level, so you can tack on another 3mm to the top of their head.
So if the 1/65 is correct, then the figures should stand about 28mm tall to the top of their head, about 25mm to eye level (discounting the base of course).
I think the people who have been complaining about the vehicle scale being "off" when compared to the troopers is because the vehicles are probably done to 1/65 just as the previous poster said they were (no reason to doubt that), but that a DIFFERENT value was used for the average height of a soldier. Maybe they decided that the average soldier was 6' tall (but that's WAY above the average height of a typical male worldwide by quite a bit).
The problem you will have trying to resize your terrain is that you want the doorways to look right when a soldier is standing near them. Nothing else really matters. Scale the doors right, and the rest follows. Besides, windows can be any size, streets can be wide or narrow, lampposts can be tall or short. But a door to a typical industrialized city building is pretty much the same. It will be cold comfort if you scale them perfectly to 1/65 only to discover the average minis is 31mm tall, and they all look like they need to duck to walk under a door.
So unless somebody with access to an actual mini will chime in with "I just measured the third marine from the left in the promo piccy and he stands "Xmm" tall" you might as well wait before you start in on your terrain.
Just my two cents.
Steve