These phrases mean basically the same thing. Possible meanings are 1) "I will place young people as their leaders, and those young people will rule over them" or 2) "youths" is a metaphor for simple and foolish men. Alternate translation: "I will place over them leaders who are immature, like young people, and those bad leaders will rule over them" (See: [[rc://en/ta/man/translate/figs-parallelism]] and [[rc://en/ta/man/translate/figs-metaphor]])
Here the word "I" refers to Yahweh. This can also be stated clearly. Alternate translation: "Yahweh says, 'I will place" (See: [[rc://en/ta/man/translate/figs-explicit]])