You’re mixing up your plans. The Manstein Plan of 1940 completely altered the Schleiffen Plan of 1914. The Brits were very prepared for the 1914 plan and that is why they were positioned where they were positioned.
Schleifen himself warned that the Germans had to use a risky economy-of-force (undermanned force) across the main front in order to make the right wing strong enough. In 1914 it just barely failed because the Germans did not accept enough risk to give the main attack quite enough mass.
Let the right sleeve of the right-most soldier brush the Channel.
Dude, you’ve got it backwards. Heinz Gruderian was the architect of victory in France in 1940.