Steps to repro:

1. Open Unity;
2. Open attached project and ’test.unity' scene;
3. Notice that there are 2 same tree creator prefabs on the scene - one is painted via Paint Trees tool of Inspector's terrain component and the second is the same tree prefab dragged to the scene view;
4. Scroll out in the scene view;
5. Observe shadows in the scene view.

Actual result:
Shadows from painted tree disappear faster then shadows from dragged prefab (see attached actual.gif video).

Expected result:
Shadows from painted tree prefab should disappear at the same moment with the dragged prefab. Expected behaviour could be found with SpeedTree models - in this case LOD levels preserve same values (see attached expectedSpeedTree.gif video).

Notes:
- Reproducible in 5.4.0b5, 5.4.0b4, 5.3.2f1, 5.3.1f1;
- Reproducible on OSX 10.11.3;
- Doesn't reproduce for SpeedTree models.