Behaalotecha 5779. Leadership: Guidance or Empathy?

Reading the news nowadays, it feels like we need leaders.
In our parsha too, Moshe experiences a leadership crisis and God instructs him to supplement his leadership with a group of seventy assistants :
אֶסְפָה-לִּי שִׁבְעִים אִישׁ מִזִּקְנֵי יִשְׂרָאֵל אֲשֶׁר יָדַעְתָּ כִּי-הֵם זִקְנֵי הָעָם וְשֹׁטְרָיו
“Gather for me seventy men of the elders of Israel, whom you know to be the elders of the people and officers over them”
From the language - ‘whom you know to be elders’ - It seems evident that these seventy elders are people who are already well known. However, what is the difference between the roles of “elders” and “shotrim” – here translated as officers? What is this dual role, these two occupations?
THEORY AND PRACTICE; INSPIRATION AND IMPLEMENTATION