Re:Zero episode 20, "Wilhelm van Astrea," offered a chance to cover some flashback material, and, in that, do a bit of casting. This included Kaito Ishikawa (One-Punch Man's Genos, Gargantia on the Verdurous Planet's Ledo) as the young Wilhelm van Astrea and Minami Takahashi (Hi-sCool! Seha Girls' Saturn, Please Tell Me! Galko-chan's Ojou) as Thearesia.
Same voice actor
Recently cast Fang of Iron captains include:
Kenji Nomura (Grapper Baki's Yujiro, Jojo's Bizarre Adventure's Santana)
Speaking of character listings, a fake version of the anime sites' was so well recieved, light novel author Tappei Nagatsuki retweeted it