I thought he was much more of a moderate in Netanyahu cabinet.
He is certainly not a moderate, but he is far more trusted than Netanyahu and is considered a moderating and opposing influence on him by many people. Mostly representing the interested of the defence establishment, as opposed to purely political interests (or, if you ask me, as opposed to Netanyahu's only real interest, which is himself).
[1] https://www.timesofisrael.com/liveblog_entry/defense-ministe...
It's called Command responsibility or sometimes the Yamashita principle/doctrine, after a Japanese general who was executed for horrific crimes committed by troops not even under his command, but in his area of responsibility (they were naval troops in the Philippines, he was commander of the Philippines, the navy and the army hated each other; he pulled out of Manilla in order to wage war in favourable terrain, the naval infantry commander refused to follow him and fought a brutal urban battle that destroyed the city, and on purpose killed more than a hundred thousand civilians).
EDIT: Asking genuinely on Gallant all I know is he was minister of defence and had a felling out with Netanyahu.