I need to find a way to either isolate the contours that need to be identified as the contours of an arrow from those that are part of other shapes.

isolated arrow being recognized while lower arrow is not

Here is an example of the problem where the lower construct shows an arrow with it’s contours connected directly to contours of other shapes which are not part of the error. The upper construct, however, has the arrow contours isolated from those of other shapes and can therefore be correctly identified as an arrow.

I am using the logics proposed in How to detect different types of arrows in image? to detect arrows inside the image which only works for isolated arrows so far.