I agree that Trump is clearer on his goals than most politicians are, but that’s not likely for the reasons you’re thinking of. Trump is clear on his goals because his goals are psychotic; they’re the goals mechanically forced on him by his personality disorder (malignant narcissism).
Trump’s actual goals are never the ones he states openly as president, since everything he says is a lie (as is true of most politicians, the difference being only that most politicians’ sociopathy isn’t as overt or terminal as Trump’s). What Trump wants out of every situation is for him to win. Period. That’s what every moment of his presidency is about as far as he’s concerned. Trump needs to win and everything he does is a transaction to make that happen. He’ll betray everyone who gets in the way and who doesn’t worship him as a winner.
As for the paradox you raise, here’s how both statements can be true. Trump is a transformational figure, because the egregiousness of his evil symbolizes the greater malignancy of neoliberal culture. His evil is embodied by his severe personality disorder, and that disorder causes him to be so monstrously selfish and narcissistic that he feels no commitment to moral principles. Consequently, his conduct is purely transactional, meaning that he feels free to “sway with the wind,” as you say, with whomever can help him win from day to day.
The paradox is dispelled, then, by a distinction comparable to that between climate and the weather. The importance of Trump’s radical presidency is a function of the rise of American evil (neo-fascism), which is a longer-term event stretching back especially to the corruption of the Republican Party since Nixon. Simultaneously, the pettiness of Trump’s daily behaviour is due to his subhumanity, to his egregious mental disorder which is, by comparison, a smaller-scale phenomenon.
All clear now?