The surprised and beaten Allied armies never lost contact with each other due to a substantial list of set-backs during the French concentration and advance.
The Allies get all the credit in the world for having prevailed in the campaign... indeed it is something that one is reminded of weekly in Napoleonic history, and during this bicentennial period, hourly.
But to suggest it was their brilliant military planning that brought about the successes of June 16th and 17th flies in the face of reality. Napoleon's plan would have resulted in the occupation of the Nivelles-Namur road on June 15th without corruption of his orders, the morning of June 16th with the corruption of his orders but absent major treason, or a decisive victory over the Prussians on June 16th without more treason (to be revealed).
The Allies received a lot of good fortune to survive the initial moves of the campaign, and then responded with near perfect execution to complete the victory. I can understand why the personalities of the time were loathe to admit their good fortune, but today we should be able to dryly see the reality of it.