The resulting format of each bit is slightly different, and the default behavior of napoleon is related to the known data types in the python documentation and it is a bit condensed ( numpydoc bit like it appears in the documentation line). Below are examples of each using the default sphinx theme.
The problem in astropy tracking issues, which states napolean , is a tight dependency for IPython , and they have migrated from numpydoc to napolean .
They mention that it has more stringent syntax requirements, but I have not tested too much to comment on this.
napoleon

numpydoc

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