In the end the consultant goes home and the team implements. Planning is an overhead function. True, albeit an essential one. The best way to manage an overhead function is determine ahead of time how much time you are going to invest in it and then make sure everyone makes the best use of that time budget. As much planning as you do you can always do more yet nothing happens until you stop planning and take action.
Balance is the key.
We recommend devoting two intense, dedicated days annually to regenerating the plan. You build a fresh plan based on where you are today based on the passions and competences of the team you have today. The key is to commit to a planning budget up front . Then scale your planning to the budget. Too often I've seen organizations blow their planning budget with a big annual effort that doesn't leave time for periodic follow-up.