"The idea that strategy could be brilliant and its execution poor is simply wrong."
In 2010, Roger Martin wrote an HBR article challenging the idea that strategy and execution are separate concepts and that great execution trumps a great strategy. His argument was that if a strategy produced poor results how could it be called "brilliant?" Could a broadway play be "brilliant" if it closed after a week? Could a political campaign be called "brilliant" if the candidate lost? Yet in business a line has been drawn between those who "think" and those who "do." If the results are good the "thinkers" get the credit. If the results are poor, the "doer's" get the blame.
A plan is not a strategy. Goals are not a strategy. Mission statements are not strategy. Good strategy is about how to execute the plan, hit the goals, and accomplish the mission.
Strategy is only as good as the results it gets.