The problems are not visual but epistemic. If the author didn't specify enough to produce a useful chart, then it's going to be the diagram equivalent of stock images thrown on a finished presentation by a lazy intern. You can't rejection-sample away this kind of systemic fault.
The simple truth we're about to realize is there is no free lunch: a tool cannot inject more intent into a piece than its author put in. It might smooth out some blemishes or highlight some alternative choices, but it can't transform the input "make me a video game" into something greater than a statistical mix-mash of the concept. And traditional tools of automation give you a much better, more precise interface for intent than natural language, which allows these vagaries.