A History of the Peninsula War II. From the Batto the End of the Talavera Campaign

Napoleon, on quitting Spain in January, left behind him as a legacy to his brother a comprehensive plan for the conquest of the whole Peninsula. But that plan was, from the first, impracticable: and when it had miscarried, the fighting in every region of the theatre of war became local and isolated. Neither the harassed and distracted French King at Madrid, nor the impotent Spanish Junta at Seville, knew how to combine and co-ordinate the operations of their various armies into a single logical scheme.
Ere long, six or seven campaigns were taking place simultaneously in different corners of the Peninsula, each of which was practically independent of the others. Every French and Spanish general fought for his own hand, with little care for what his colleagues were doing: their only unanimity was that all alike kept urging on their central governments the plea that their own particular section of the war was more critical and important than any other.