By virtually any standard, Rex Tillerson was a terrible Secretary of State. That said, he isn’t stupid or crazy, and he probably exercised some small degree of restraint on a president who needs all the restraint he can get. Now, that will be gone, and Trump will have yet another hawkish enabler at his side when he makes decisions on war and peace.
I satirically promoted Ivanka for Secretary of State in 2016 on the ground that she could understand and spin her father better than anyone alive. That wouldn’t look too bad right now, would it?