Shadows on buildings in distance

Hi, we have an issue with shadows on building disappear from LOD on buildings, so they look very 2Dish. We have tried to bake the shadow into diffuse map, but this is a very time consuming effort and will not look good when you’re close to buildings.

Secondly we are thinking to bake this shadow into the AO map. What would be the best way to approach this?

Here is a before and after adding shadow to diffuse map:

before.png

After.png