Before you go off and modify all your estimates, I don't know if we should
100% trust that figure. Though they also give a number of 393.7mm, suggesting precision (even though that's just 15.5 inches converted to metric), the fact that it happened to work out so specifically to such a nice round number gives me pause. So, I decided to check how tall that 2.3622m figure would make the other human characters from the cutscenes:
So, if that's the height of a marine, Mengsk is 6'8," Hansen is 6'3," and Nova is 6'4." That's really
very tall for a woman. I think it's much more likely that either Sideshow rounded up the statue's height from a more precise figure for convenience in their advertising, then converted the rounded up numbers to mm, or the statue is actually slightly larger than 1/6th scale, but they rounded it to 1/6th scale anyway. I doubt Blizzard intended for its characters to be quite so tall.