I don’t believe the aim of every leader should be to treat every person the same. In a group, you obviously say the same message to everyone. Past this point, you must realize that each person isn’t the same as another when it comes to what they do with that communication. Each person will be informed, motivated, related with, and learn differently. Treating everyone the same is a convenience for the leader, not a principle of leading.
Know the people that you work with and lead. Get to know what matters most to them. Those people that are less willing to be lead will closely monitor the character of leaders with suspicion. Everyone being treated the same is a very low bar to set.