One thing I find unrealistic is that trees have no effect whatsoever on missiles, which is unrealistic.
If fog affects IR seeker (which is realistic), then why not trees? A dense forest, like the one in the picture, should interfere with IR sensors. The thick branches, should detonate or damage the seeker head, rendering the missile unusable.
Moreover, missiles are full of flight surface (i.e. fins), which are thin and would be damaged upon cutting branch after branch.
Moreover, the terrain should have effect than just multipathing. For instance, the scenario shown below will interfere with radars; I am not entirely sure if the radars compensate for this (especially early ones) or not. PD radars should see multiple targets I assume.
