Washington (CNN) The parade of administration hopefuls passing through the Trump Tower lobby includes quite a few who have worn stars on their shoulders -- the kind of military men President-elect Donald Trump derided during the campaign as "embarrassing."

Trump is interviewing current and former military brass for Cabinet positions, including erstwhile CENTCOM commander Gen. David Petraeus, retired Marine Corps Gen. James "Mad Dog" Mattis and the former head of Southern Command, Gen. John F. Kelly. He's already appointed retired Gen. Michael Flynn as his national security adviser and met with Adm. Mike Rogers, head of the National Security Agency and US Cyber Command.

The unusually public process -- typically conducted behind closed doors -- has raised concerns about a Cabinet more heavily weighted toward military rather than civilian leadership. At least one of Trump's potential picks would require Congress to waive legal barriers to service members serving in civilian positions.

And some of the military men in Trump's orbit have faced questions about their performance or judgment. The names being floated may reflect the President-elect's predilection for leaders with a "tough guy" profile, but they also mark a 180-degree turn from some of the insults he leveled at military figures during the campaign.

Trump's pivot to Pentagon expertise as an incoming commander in chief isn't that unusual. US leaders have long turned to military experience to help them guide the civilian ship of state.

"It's not unprecedented," said Richard Kohn, professor emeritus of history at the University of North Carolina, Chapel Hill, who pointed to three four-star generals President Barack Obama included early in his administration.

"You put people of distinguished accomplishment in these positions," Kohn said.

Obama named retired four-star Gen. James L. Jones as his national security advisor, retired four-star Admiral Dennis Blair as his director of national intelligence, and retired four-star Gen. Eric Shinseki as his secretary of the Department of Veterans Affairs. Both his predecessor, President George W. Bush, and President Ronald Reagan named four-star generals as their secretaries of state.

"What might be unusual is the public way in which this is being displayed by Trump," said Kohn, who focuses on issues of war and security, "so we hear about all these people being considered, as opposed to having the announcements after they've been decided."

Also unusual: Trump's comments about military figures during the campaign, which were perhaps unprecedented for a presidential candidate, one who presumably learned respect for military leaders as a military academy student in his teens.

Trump repeatedly criticized a Gold Star family whose son died in the line of duty in Iraq. He said Republican Sen. John McCain of Arizona was "not a war hero" because he'd been captured as a Navy pilot in Vietnam. He proposed committing war crimes, such as killing the families of terrorists, despite the Pentagon's opposition to such policies and in November 2015, boasted that, "I know more about ISIS than the generals do."

At a September commander in chief forum on MSNBC, Trump said military generals were "embarrassing" to America and had been "reduced to rubble" under Obama. And he suggested that he'd clean house if he got to the White House, appointing "different generals, to be honest."

As Trump began considering generals for a slew of Cabinet positions, former House Intelligence Committee Chairman Mike Rogers told CNN's "New Day" last month why there are concerns about "a military attitude in the civilian position."

"When you get to that defense secretary role, it has to be a broader, strategic impact brought to any decision you make in any strategic event you make around the world -- including, by the way, acquisitions of weapons," Rogers said. This is one reason for a 1947 law that requires a seven-year window before military leaders take the helm at the Defense Department.

The question of how to balance civilian and military power has been around for millennia. Plato wrestled with it around 380 BC in "The Republic," a Socratic dialogue that examines the order of a just city-state. The question, as he put it, is 'who will guard the guardians?'

More than 2,000 years later, France's World War I Prime Minister, George Clemenceau, declared that "war is too important to be left to the generals." His point was that broad strategic considerations are best guided by democratically-elected representatives of the people and not an elite group of tactical experts.

Howard Gardner, a psychology professor at Harvard University, said Trump is drawn "toward leaders who have a 'tough person' profile" like Russian President Vladimir Putin, "what psychologists call 'the authoritarian personality.' " Gardner added that, "We have yet to see what happens when those leaders don't bend to Trump's will."

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Trump seems to be choosing people who supported him throughout the election process or individuals who signal beliefs and loyalties that will appeal to his constituencies, Gardner said. "Since a big source of support for Trump were military leaders and veterans, it is natural for him to turn to that constituency."

Gardner added that, "Also, they tend to obey orders."

Kohn notes that many of Trump's prospective hires parted ways with the Obama administration, and in cases such as Flynn's -- who was pushed out as head of the Defense Intelligence Agency in 2014 after two years -- have been quite vocal about their unhappiness taking direction from the current White House.

"It's interesting to me that President Obama chose three people who were known to be very independent-minded, known to have disagreements with the Bush administration before him, and Trump is doing the same thing, picking people who had disagreements with the Obama administration," Kohn said.

The "different generals" making the passage through the Trump Tower's lobby include Mattis, who is reportedly being considered as a defense secretary, though he would need a congressional waiver from the 1947 National Security Act to take the job. The Washington-state native, who retired in 2013, hasn't been a civilian for the requisite seven years.

Some question whether he'd be right for the job. Erin Simpson, former CEO of Caerus Associates who served as an advisor in Afghanistan to the NATO-led security mission there, has written that Mattis is a legendary commander, but ill-suited to the bureaucratic job of running the Pentagon.

"He is a warrior and a leader of men. He is not, however, a man for all seasons," she wrote on the website War on the Rocks. "He is not a politician, or a wonk, or a bureaucrat. To ask him to be any of those things would be like trying to keep a wave upon the sand."

Kelly, Mattis' friend and Marine Corps colleague, is reportedly being considered as a possible Homeland Security secretary. And Petraeus is on the list of candidates for secretary of state.

Petraeus is widely respected for his experience on the battlefields of Iraq and Afghanistan and for developing counter-insurgency strategy -- alongside Mattis -- that is credited with reversing the violence in Iraq in 2007.

But the former CIA director is burdened by his guilty plea to a misdemeanor for mishandling classified information. Petraeus gave classified materials to a woman he was having an affair with and then lied about it to the FBI.

The other generals Trump is considering are also shadowed by controversy. Flynn, the future national security advisor, has potential conflicts of interests because of consulting work he has done for Turkish and Russian clients. And he has expressed views on Islam, terrorism and Asian countries that many see as extreme. Human Rights Watch has said Flynn has "contempt for the laws of war" and "a deeply disturbing disregard for human rights."

Rogers, the head of the NSA, most recently courted controversy by visiting Trump Tower without informing his superior officers.