Someone who can’t extrapolate a short fic idea from the prompts just isn’t trying. A lot of people don’t care about getting an exact prompt. They’re trying to convey the tone of fic they like. So, if all the prompts are about Aziraphale/Crowley doing epic historical world saving things in various points in history, the recip clearly likes historical settings. So write a snapshot of something in a historical period of your choosing, no epic world-saving needed.