If Trump took nuclear docs to share with, ex, the Saudis, he would certainly have needed help inside the WH to find the docs that would be of interest to them. Because, Trump himself certainly doesn't know the technology, so he wouldn't know which info the Saudis would want. And he probably wouldn't know where to find such documents in the first place. He would have needed a technical expert with some knowledge of how the government stores classified info in order to get the good stuff. Taking everything would be an option, but that's probably hundreds of boxes of stuff.
But still, that first "If" is important.