Allow me to cite a relevant example from US history.
The US Attorney General is a member of the President's cabinet, and must be confirmed by the US Senate, but
serves at the pleasure of the president and can be removed by the president at any time.
On the evening of 20 October 1973, a Saturday, US President Richard Nixon ordered Attorney General Elliot Richardson to fire special prosecutor Archibald Cox. Richardson refused, choosing to resign instead.
Nixon then ordered Deputy Attorney General William Ruckelshaus to fire Cox. Ruckelshaus also refused and resigned.
Nixon then had Solicitor General Robert Bork sworn in as acting Attorney General, and ordered Bork to fire Cox. Bork did so.
All of that happened in a single evening, without any action by the Senate. Almost a month later, a federal judge ruled the firing of Cox was illegal. Under pressure from the judiciary, from congress, and from the American people, Nixon allowed Bork to appoint a new special prosecutor.
If a US President orders the use of nuclear weapons, and dismisses cabinet members until he can promote a toady willing to support that action, a federal judge might well rule the action illegal a month after the damage has been done, the House of Representatives might well impeach the President, and the Senate might well convict the President, removing him from office.
What you seem to be saying, therefore, is that the existence of safeguards that would close the barn door long after the horses have left give you a compelling reason to vote for Trump.