Yuri-Hime has been trying to do more fantasy series. The editorial direction seems quite openly to be trying to hit the trends from Narou-kei, leaning into tropes. That's maybe not the highest of creative aspirations, but I can't say it doesn't make sense for YH to be doing yuri versions of popular fare.
Anyway, out of those fantasy stories built on cliches, chapter 1 of Helpless Saint and Powerless Princess is the one that I think has executed better than the rest on being a crowd-pleaser.