Source novel: https://www.novelupdates.com/series/the-villain-daughter-enjoys-her-seventh-life-as-a-free-spirited-bride-hostage-in-a-former-enemy-country/
The story is time-travel politics/romance. There's no "revenge for past life" plot here.
It really shouldn't be compared to Overlord. After all, Overlord MC is strong individually, and here we have a purely managerial MC with no combat power.
Hmm, what's the difference between Rearguard and Ranger in combat? I mean, in general, not just here.
Or is it just that rearguard here means a magic-caster?