Is King Fritz I from Attack on Titan historical related to the early Germanic tribes during Roman times?

In Attack on Titan manga, there is a tribe called Eldia and ruled by a cruel chief. He enslave weaker tribes, cut the tongues of freshly captured slaves and threaten to gouge every slaves’ eyes if no one confessed.

With the slave Ymir getting the power of the Titans, he used her as way to benefit his tribe and destroy his enemies, essentially ruled the world. After Ymir’s death, he have his daughters eat their mother to inherit the Titan power and wanted Eldia to rule the world.

I am curious whether Fritz I’s actions is similar to any Germanic tribes or is it anomaly which Fritz I is just a psychopath and its cruelty is beyond Germanic tribe standard.

I did some research and the results seems to point the latter, but was I right in my research?