The moment you write a post is the moment it is convenient for you. Your audience reads on their own schedule: the morning commute, the lunch scroll, the evening wind-down. A post fired at your convenience lands in an empty room.
Pick the troop's posting times from the readers' day, not the writer's, and keep a genuine quiet period overnight. Then change one troop's hour and watch its results for a cycle before moving the others. Timing experiments are cheap and the differences are usually not subtle.