, the Monarch is slightly shorter, at about 45.5 in, or 115cm. There is only a .5 inch difference between the two though.
Waist wise, the Monarch is a 33-37 pant size, compared to the 31-35 pant size of the Fatigue. Using a belt and suspenders would help though, if they fit too big.
I believe, if I'm correct, that this years fatigues are the same length as last years, maybe a 1 inch difference, so the Monarchs fit quite a bit baggier in the waist and legs, but they are approx. the same length.