okay so I actually find your take of the story interesting but I also find it very flawed since you could literally flip it
1. You say Eldians are descended from Germanic tribes but what you are missing is that they are Eldians, point-blank-periodt. This is a fictional story https://twitter.com/CatsAreCuteAsf/status/1259544342051663872

even if I were to depict Eldians with Germanic tribal attires Marleyans with Roman armors and Hizuru with a shogunate system, everything is still fiction Eldians are still not Germanic, Marleyans are not Romans, and Hizuru are not Japanese.

2. What you're pretty much ignoring about the Eldians is that, following your logic, they are both White Germans descending from Germanic tribes and Jews(?), On one side their ancestors were Germanic tribes but on the other currently the ones living in Marley are Jews (armband)

and the latter are being oppressed by descendants of Romans and Turkish people too, because the Mid-East East Alliance's soldiers ressemble Ottoman soldiers ??? this just falls apart and it looks like a very far reach to connect the story somehow with reality

3. I think you missed Billy Tybur's speech, where he literally explained that Marley didn't do shit during the end of the war but that the 145th King Karl Fritz (German according to you) himself ended the war because he was saddened by Eldian's (your Germany's) sins and genocide

so he escaped and let his own people kill each other trying to safe only a part of them, leaving the rest on the mainland to fall under Marley's rule, who would only use them as weapons as you correctly said to widen their empire's borders. Thus, resulting in other nations trying

to wipe out all Eldians (like Udo or Kiyomi explained). Now I would gladly like you to find some type of comparison to real world history bc it seems u like to do that a lot

4. You mention the King Fritz's Ideology, which was meant for all royal descendants to refuse saving Paradis Population (Eldians) from Marley's and the rest of the World's imminent attack, which totally contradicts Eren's actions while belonging to the same group of people.

People in Paradis where forced to remain ignorant and wait for their annihilation without knowing who was coming for them. I dont see any way of correlating this with Germany or Japan's imperialistic ideals. In any case these ideals are present in Marleyan politics, which are

literally depicted as the bad ones in "current time" for most of the series, considering they are the ones putting Eldians in ghettos and indoctriniting them, and causing most of the pain in the series. So, I don't really see where you see Isayama praising Imperialism here

5. Have you read the latest chapters???
You literally ignored the whole plot point of "we need to make an alliance to stop Eren from commiting genocide and finish the faction that's trying to support him even though we don't want to kill more people but rather just talk to Eren"

6. Give your hearts as a glorification of alt right and white nationalists??????
Let's make a comparison since you like them so much.
Paradis people live in a somewhat Medieval Europe with medieval mentality, tell me, in what war during medieval times did they not use that type

of abstract phrases glorifying sacrifice to get sodiers' morals up???? And about this, the whole militaristic world of Paradis at the time was centered on one thing: Titans. How is there any type of comparison to that??? Paradis people fought titans for mere survival or bc

they indirectedly forced them to stay within the walls, unable to investigate the rest of what they didn't know was an island, doomed to wait for the time where resources within the walls become scarce and, how the King wanted, to wait for their deaths living like cattle.

7. Eren's actions are depicted as everything but sympathetic. Again, have you read the latest chapters???
The people who know about the rest of the world by first hand within Paradis (SC's main cast) see Eren's genocide as the option Eren has chosen bc he doesn't see any type of

hope in humanity while they (Alliance) still believe that there has to be another way and are ready to stop him or at least confront him, meaning, not sympathizing with Eren's view.

So, I may be wrong on some points but I would gladly like you to reread the whole manga bc I've done that and for some reason have never come to that conclusion but rather the opposite, and I know i'm not the only one.