I can’t say this for sure, but I think the $300 billion figure refers to better purchasing across all the departments of government. As much savings can be achieved by buying Eurofighters rather than the F-35. Also, by buying French frigates rather the Littoral Combat Ships. But, of course, we’d like American companies to produce the armored vehicles, warplanes and warships we acquire. And, if they were cost competitive, we’d be able to sell such things to allied countries, improving our balance of trade deficit. With regard to pharmaceutical drugs, if we re-visited our product liability laws, we could return their manufacture to the U.S. Again, this would mean jobs, improve our balance of trade, and improve our readiness to deal with response to disease. There all lots of movings parts to all of these considerations. Bottom line is that the government is so f-ed up, that we’re going bankrupt and our economy is screwed, our military and our health care are weak.
You have certainly nailed the fundamental issue with Trump. He often speaks in incomplete sentences and interrupted thoughts. Supporters then read their own ideas into his positions. He becomes all things to all people. Others have more derogatory words for this behavior.