Well if there is shadow issues I would check your “indirect light” intensity. Bringing the light intensity up will usually land up blowing out the lighting but the use of indirect lighting intensity is how you can go about changing the shadow density. Try a very large value to start, something like 20, and back it down until you reach a good balance.
Another useful option is to make use of HDRI maps in the Postprocess volume to control indirect lighting with out having to rebuild lighting.
In the example there are only three light elements. 2 exterior and 1 interior and the PP controls the indirect lighting only as to filling the volume of space with a base.
Basically anytime you see indirect lighting that would be your means to control shadow depth.