Yes, Because you are " Adding" the one component on top of the other..
What I do occasionally is to create a vector around the top component, then select that vector and the bottom component and delete that portion of the bottom component.
It will leave you with a hole in the bottom component.
Using that same vector,
I then will create a new component to the fit that space with the shape and undulations that I think looks best.
Sort of putting together a puzzle...