Value Input From All Team Members, not Just Results
When working on ambitious, multi-year design strategy projects, it's important to consider the decision-makers' experience who are engaging in your process. In my experience, when people reflect on their careers, they are much more likely to remember how they felt being part of a specific project or team than the nuances of the actual end-deliverables.
Never forget that after you give your final presentation, your perfectly formatted slide deck will be cut up and copy-pasted into 100s of other decks and documents; it will take on a life of its own. Three years on, key decision-makers may not even remember your original strategy presentation. Still, they will remember how they felt being a part of that process, whether they felt like they had input, whether they felt represented in the ideas outlined, whether the right trade-offs were discussed, etc.
Ultimately it will be those people who carry the strategy forward long after you have finished the project. Their understanding of the vision and their buy-in is critical, maybe more so than any glossy visual mocks or the perfect product narrative.
The best strategies are those created with significant input from decision-makers along the way, such that they feel a sense of ownership and buy-in before the final presentation has even begun.