Hi! Saw your lonely plot and I've got a few options, thought throwing them here might be easier than PM ^_^

Walter Brownhill has a lot of experience in the Ministry & a mild amount of authority; he works in Magical Accidents & Catastrophes. His daughter @"Lucy Brownhill" is a current 6th year, so he could've potentially got the idea to write from her.

Fortitude Greengrass has considerably less experience and authority but he's younger and might be seen as more approachable? His sister is a 6th year also, so Addison could feasibly have gotten the name from her. (Clementine Greengrass).

Also Ernest Mulciber isn't active right now but he works in the Department of Mysteries and derives particular pleasure from crushing the dreams of ambitious Hogwarts students who want to be Unspeakables, so. If you want him to have a very unpleasant exchange, there's that xD