He has been a bit of a statto since he was a 13-year-old, when he used to write the line-ups and qualifications of all the players of the first division in a notebook that his father gave him.
With advancements in modern technology he now relies a lot on computer software to help him rotate his squad to get the most from them.
One thing is certain - Benitez takes his job very seriously and is determined to succeed at Liverpool as he did at Valencia. If he can do that then I personally don't care how he picks his team.