Recently, at an academic conference, a colleague and I were talking about precisely what parts of Trump's tenure are going to be the most distinguishable from a hypothetical Clinton administration. When it came down to it, I think we both thought that national security policy was the area that would be most similar. Trump has recently been criticized for the amount of Syrian, Iraqi, and Yemeni civilians killed by the US or its partners in the past year or so. However, it is likely that the rise in numbers would have occurred no matter who was in office. Battles against ISIS in Iraq and Syria were coming to their horrifying but almost inevitable conclusions: the last strongholds of ISIS being besieged and bombarded. Civilian deaths are bound to increase when states bomb population centers from the air. The results are no different here and the bombing would have likely commenced in a similar fashion with Hillary Clinton as President.
The situation in Yemen is perhaps the area where Clinton would have handled things differently from Trump. The Obama Administration was seemingly on the verge of relinquishing its support from the Saudi campaign as Obama was leaving office, a move that President Trump has clearly reversed. However, Hillary was a hawk in that administration and would have perhaps also reversed course. All in all, while Trump's words set him apart I'm not sure his national security policies actually do...at least not yet.