GW does what it can with the stat system it has developed over the years.
There is a certain flavor to the various races though. Tau don't like
close combat and rely on their weapons to settle the score. Their stat
line reflects this with poor close combat values (Mr. Acord knows *all*
about this). Whether this dislike for close combat is a result of poor
martial skill or just a deep seated psychological hatred of getting messy
is beyond GW's scope methinks.
To me it leans towards the psychological but what do I know?
Damo