Aren’t the rears and tops of tanks and APCs not armored and heavily as the front, sides?
I can take a crack at that. Javelins attack from above, which is why they are so effective, but, many other anti-tank systems are not that sophisticated: In the vids you see them coming in pretty much horizontal, usually from the side.
If the tank has passed you, you are probably dead.
Now I have a question for our arms experts: If a typical NLAW hits a tank with reactive armor from the side, typically how big an area of reactive armor blows off?