Of course, the Cabinet is "stable."
Like it or not, President Trump took an active, hands-on approach to his Cabinet.
Ah yes, with Trump it's the old 'appointing a fox to regulate the hen house', principle; many of his appointments were lobbyists in the same industry they were appointed to regulate or they were antagonists to the regulatory bodies.
For example, for the Consumer Finance Protection Bureau he appointed the OMB director, Mick Mulvaney, a founding member of the Tea Party, who are CFPB antagonists.
Not only that, Trump appointed mainly 'acting' directors, to get around the Senate Approval process, allowing him the freedom to fire appointees at will. The big controversy in doing this is not only does it fly in the face of federal law establishing cabinets, how execs are approved, etc, it destroys morale in the rank and file of those affected cabinets, as acting directors command little respect and are seen as whimsical political operatives.
The point is, under Steve Bannon's "deconstructing the administrative state' bullshit narrative, Trump followed his advice and appointed people to undermine the departments, emasculate them, destroy them, leaving many important posts unfilled, which is what Trump did with the State Department. I will take years to restore the state department to it's full potential of it's former years. Many operatives in the state departments are trained for years, are lifers dedicated to the mission, many of whom left during Trump as they felt their services were no longer needed, and replacing them will take years. Hell, half the ambassadorships were left empty. Running a country without a well staffed state department is like flying a Boing 747 without an instrument panel, or half of the instruments on the panel are not working. Micromanaging the executive branch is impossible, but that is what Trump, someone who is used to running only a mom and pop operation, tried to do with the nation. He was wholly unfit to be president, not ot mention he couldn't hardly utter a compound sentence, who didn't read, refused to read his daily intel briefs, who spent much of his time watching TV and golfing, being more concerned with crowd sizes than anything important, etc.