@nev there's no standard. It's all customisable, unfortunately, and the default settings only link to a post by its internal ID number.
https://codex.wordpress.org/Using_Permalinks
Unless whomever's site it is intentionally are publishing permalinks by author, or using a plugin that does so, you're hosed.
@wohali that's what I suspected, but...hmm wait I got a brain wave. Will have to see if this idea works...