On the accuracy of transfer rumours, there have been plenty of studies.
this one for example analyses the percentage of correctly predicted rumours from 2006 to 2013.
The express comes in at 24.9% accuracy. This is some way behind The Guardian (34.2%), but it's not far behind the Times (27.3%), and well ahead of papers like Metro (11.6%).
The Express is not the most reliable source, but to dismiss them offhand is silly when the hard data tells a different story. They're right roughly one time in 4. The most reliable paper is right roughly one time in 3. Hardly an enormous difference.