So what became of the magnificent War Wizards?
Did Nihil already defeat them?
If not, and the Aurors must fight with them, then I think Draco has a point about combining training! I can't think of any reason why the Trainee Aurors (or at least some exceptionally talented trainees), should not be given the opportunity to learn from the War Wizards.
Perhaps the Ministry is more concerned with keeping any group from becoming too powerful, rather than the most efficient method of policing.