Use your time wisely but "over-studying" for the ATPL exams probably isn't an efficient way of improving your skills as a pilot. The best assessment you can get is "pass" which means that this is what you need to achieve.
If you are to look at the results first time passes should count for more. This says more about your ability to achieve a defined goal, with a reasonable margin.
For reasons stated earlier on this forum I couldn't transfer my exams from one country to another so I needed to re-take several of the exams I already passed. The first time I sat gen nav was with a result of 96%. More than a year later I was to re-take this exam and got 82%. I knew that I was most likely to pass the exam even without refreshing my memory very much. As long as I pass with a reasonable margin I rather spend my time reading up on things that might actually keep me alive.