If I understand you correctly and my brain actually works, you don't need Shadow Collision if you have Line of Sight and the shadows move with the enemies.
Since the calculation of line of sight and shadows work almost the same (covering the area between the lines that go from the enemy to an object's left and right edge), line of sight will have the same triggers as a shadow collision.
Of course, this only applies if your movable light sources are all attached to enemies.
It is different, if there are moving light sources that aren't attached to enemies.
But in your description, it sounds like the first case.