Great article Andrew, thanks for sharing it. You — and the leaders you cite — are spot on about taking time to think.
When I served as an Aide-de-Camp in the Army, I noticed quickly that General Officers could easily have their days committed entirely to meetings if we weren’t careful. A common technique we as aides would use to combat this, and to give them time to THINK, was to do just as you suggest: schedule a few hours each day of uninterrupted “block” time and then protect it as a higher priority than (almost) anything else. We did this both at home and in combat.
We can all take a lesson from your article. Taking time to think can be the most critical habit of all.