There is no perfect prescription for assembling a cabinet, although most incoming presidents have aimed for geographical balance and, in recent years, gender and racial diversity. Nor is there any particular order in which cabinet members are supposed to be named, although here, again, presidents-elect have sought to nail down top foreign policy and defense jobs fairly soon. On that score, Mr. Trump is only partly there, with Lt. Gen. Michael Flynn as national security adviser and Representative Mike Pompeo as director of central intelligence, but no secretary of state or defense as yet.

If there is any ideological consistency it is in the appointments of General Flynn and Mr. Pompeo. Both are hard-liners, as is true of the hard-right Stephen Bannon, whom Mr. Trump appointed as his chief strategist. Reince Priebus, the new chief of staff, seems more of a consensus pick, since his main job over the last few years, as chairman of the Republican National Committee, has been to keep as many Republicans as possible as happy as possible.

Josh Bolten, who ran George W. Bush’s transition — acknowledged by experts to be one of the best-run in recent history — calls Mr. Trump’s wide-open approach to hiring “refreshing” and its organization “peculiar.” He has no better idea than the rest of us about where Mr. Trump is headed. After all, Mr. Trump has been tinkering with his stances on Obamacare, climate change, so-called enhanced interrogation and immigration, and often seems to express the views of the last person he’s spoken to.

But Mr. Bolten, like others, seems worried that Mr. Trump, like Groucho Marx, might be trotting out his principles, while saying, “If you don’t like them … well, I have others.”

“We had a governing agenda,” he said. “The Trump folks don’t, and so their personnel are going to have to write the book as they enter office. It can be done, but it multiplies the degree of difficulty.”