Having played with this, I'd like to help. Found one advantage and one disadvantage, theoretically, in using a scope atop the sight handle.
The two curves are actually the same shape, just tilted by lowering one end of the red curve (high-mounted scope trajectory), pivoting on the 50yd zero point, and raising the downrange end of it. If the comparison is redrawn using a 250yd zero as that pivot point, with both curves meeting only there, you can see that the red curve would be a little lower than the blue one (iron sights trajectory) anywhere short of 250, and a little higher anywhere beyond.
In other words, the impact with a high scope mount lies closer to the point of aim from 100 to 300 yds. That gives a longer point blank range, but places your soldier's noggin another inch above cover.