I don't think the reference is to just Mattis and Rogers, but to key military leadership in general (ha!)
House is a good place to start, but then he needs to clean house in the military.
Obama loyalists made that a mission to comp the military for decades to come.
Lots of worms in the woodwork, although the majority are Patriots who joined, and stay, for all the right reasons.
But the columnists need to rooted out and gone.
Audit the field grade promotion boards. Fraud is fraud. Everyone serves at "the pleasure of the President". anti-MAGA Columnists are easy to get rid of.
Kansas = Leavenworth (Major secure military prison)
But the lawsuit in Kansas challenging the FBI credibility is noteable, too.