Here it says that He will strengthen the Cholah. Above (4), it discussed curing it!
Radak: Here, Cholah includes Nachalos (weak) and Cholah (ill) above. "Achazek" includes curing ? also this strengthens!
Why will He eradicate the fat and strong?
Rashi: It pushes its colleagues [Radak ? from the pasture. I will eradicate their strength.]
Radak (according to the Nimshal): These are strong oppressors in Yisrael. They oppress the poor and weak.
Radak citing Targum Yonasan: I will destroy the sinners and liable.
Malbim: Not only will He guard the flock from Chayos and bandits ? He will judge among the flock itself. The fat and strong, i.e. the rich, take all the abundance via their wealth. The strong, who take via force, I will destroy.
What is grazing "b'Mishpat"?
Radak: What is proper ? the weak should not graze more than is proper for them.
Radak citing Targum Yonasan: I will conduct My nation with Din.
Malbim: The entire flock will graze equally.