Improve the suggested list of labels in "Related Labels" module

The labels suggested under "Related Labels" module aren't always related to the content,
for example if there are two pages with Label1 and Label2, and third page with label3, we select Label1 then add Label2 from the related labels module, it will show no results as no pages have both labels, however the "related labels" module still shows label3 and a list of labels that aren't related to the results or the labels selected.