Hegseth was only O-4 at the end of his career, which was basically as a reservist, sidelined as an insider threat due to his white nationalist tattoos.
When Hegseth was an O-3, he was an instructor teaching counter-insurgency in Afghanistan. That was his entire time as O-3.
As a lieutenant, Hegseth 'commanded' a small squad stationed at Guantanamo Bay. That was his only experience in command.