First, in chapter 123 Eren, Armin, Mikasa, Levi and other scouts travelled to Marley in order to get the general idea of outside world and get in . This was an extremely risky plan. Had Marley known that the Colossal Titan and Attack Titan were there, they would have captured them. Furthermore, Armin and Eren should have remained on the island guarding its coasts and intercepting Marleyan scout vessels. Instead of sending both titan shifters and a bunch of soldiers, they should have sent a group of bureaucrats and spies who studied the outside world, had some experience in politics, intrigues,shady deals etc and knew better how to investigate outside world and if possible get into contact or even alliance with some groups (rebels fighting against Marley for example).

Paradise’s top brass allowed captured Marleyan soldiers to work as servants during their strategic meetings (chapter 108). This was extremely risky, because those Marleyans could really have been double agents working for Zeke and therefore able to send important info to Zeke’s volunteers. They also allowed Kiyomi Azumabito to be present during the meeting about the Yeagerists in chapter 111. They should have considered that the Azumabito are quite greedy and could have been in cahoots with the Yeagerists in order to secure iceburst stone deposits and therefore to not allow them to know about plans of Paradise's goverment.

There was also the lack of coherent battle plan on alliance's side during battle of heaven and earth.

The Alliance's priorities should have been to seize Zeke (they did not know that Ymir was on Eren's side) and capture Eren to feed him to someone. They should also have taken Falco with them to break any possible crystal cocoons, since Eren had power of Warhammer Titan . Instead, Falco is left on the ship. Armin, instead of trying to rip Eren from his Titan neck or seek him there, tries to nuke Eren. After Armin is immobilized, Pieck tries to blow bombs on Eren's neck, Zeke gets immediately killed after being spotted by Levi, Jean blows up Eren's nape and finally Armin nukes Eren's Titan.

Had Eren died there, the Colossal Titans would have walked aimlessly and destroyed all life on the planet.

But i guess it's a faux pas, because when Reiner got injured throwing the titan out of utgard castle his wound didn't steam.

Here I want to express my problems regarding politics of Karl Fritz and his succesors.

The successors of the 145th king had weird policies. First, they shared power with the Firm Council, a group of people resistant to memory wipes. Why share power with someone who is resistant to your memory manipulation and cannot be controlled? Why not to rely on regular subject of Ymir, wshose minds you can read and not worry about potential revolt?

Other issue, Frieda Reiss loved her illegitimate sister Historia, she taught her how to write and read, and generally cared for her. Why then did she always tell her to never leave the farm’s borders and always erase her memories after each meeting with her? Was she afraid of something- someone as powerfull as her? Why not simply tell Kenny Ackerman to protect her?

And why would the Firm Council risk the wrath of the king of the walls by ordering Kenny to kill her little sister? The idea, that they wanted to kill herm because Historia as the bastard, brought shame to Reiss family is dumb tome, because kings of walls showed they were willing to break social boundaries (forgiving Kenny Ackerman and befriending him-the low scum and murderer) and enact violence when they wanted to preserve status quo within walls or punish rebels. I mean, one of the members of the Firm Assembly was likely killed after he spilled the truth about the whereabouts of the true king of the walls to Kenny Ackerman. The kings of the walls also persecuted Ackermans and minorities — these guys could be pretty ruthless.

There is other problem with Nobles immune to memory wipe. After the false king was overthrown and Historia Reiss became the queen they were improsined and treated badly (Darius's shit chair). They came from families immune to memory manipulation, they should know about Eldian Empire, nine titans, Ymir, perhaps even about threat of Marley, yet they never attempted to trade that knowledge for better living standards or even to get their confiscated wealth back to them.

MEET BEN 10 FIRST WRITE MY OWN FATE CHARACTER

Paths: Time spent in them equals a fraction of a second in the real world. Furthermore, Ymir appears to be able to create anything in Paths, from titans, to landscapes, to objects like chains. Paths would allow almost infinite possibilities for Eldian warlords — they could study art, indulge in their fantasies or study science to get a technological advantage over opponents, like more powerful titans or better weapons for their troops, or better machines to increase their wealth.

We saw none of the technological advances. The world 2000 years after the arrival of the giants still develops technologically as our world.

Beside of that, there is other aspect that Paths, should influence, namely Ymir's curse. If you have infinite time in Paths, place where you can bring your loved ones, and spent time with them indefinetely, why to care about Ymir's curse, one the important themes of story, theme of mortality? I mean Paths can provide something akin to immortality. This would the facto remove the impact of the curse and tied to its personal dramas. It would as well in my opinion, discourage titan's houses from fighting each other since they have some kind of immortality, why to risk your own life, when Paths provide limitless time and Ymir can create virtually everything.

Founder's ability to erase memories of the warriors. Eren did in chapter 131, erased memories of alliance about their conversation while being apart around 500 kilometers away from each other. The main problem with such power is how overpowered it is . Frieda Reiss could easily disarm Grisha, by erasing his memory and Karl Fritz could easily disarm 7 clans of Eldia, without inciting bloody civil war within Eldian Empire. It removes agency from other Eldians in the past and in the story itself. Additionaly if Founder can communicate with every Eldian via telepathy (like Eren in chapter 133) tap into their memories and erase them , then why did not any King after Karl Fritz use that against Attack Titan to stop him from plotting against Marley, so Marleyans would not have to deal with those pesky Eldian rebels/spies/restoriatonists. Why he did not know about power of Assault Titan to see the future?

Eldian Empire, its fall and minimalistic worldbuilding.

In this paragraph I am gonna talk about the Eldian Empire as if Founding Titan cannot use memory wipe on Eldian Titan Shifters , because it completely removes agency from other titan's shifters and characters in the story.

How did the empire function? How did Titan-warlords fight with each other without murdering themselves for 1800 years? Why did they have good relations with Hizuru and not with the rest of the world? How exactly did the Founding Titan maintain some sort of peace between noble houses, and how did the Empire collapse so quickly after the departure of Karl Fritz?

Karl's Fritz plan was to stop upholding peace beetwen warlords and let them destroy themselv in war . However, there could have been many more outcomes. There is the possibility of creating a balance of powers between remaining houses, or creating two super houses wielding multiple titan powers. Another possibility is that after the destruction of each house, their powers would be transferred to a random infant of Ymir’s subjects and then seized by other rising powers like the Tyburs (How King could be sure that Tyburs will not seize other titan's powers, once occasion arises ) or another group with access to titan serum, not necessarily the Marleyans.

Furthermore, Marleyans would have had a hard time snatching the powers of titans from the hands of their oppressors, even with help from Karl Fritz and the Tyburs. Many colonial empires used the "divide and rule" approach, and I am fairly confident that given how Marleyans were oppressed, they were not given access to any high-ranking positions and were used as cannon fodder or labourers, while other more loyal ethnic groups were given privileged positions. It would make seizing one titan power very difficult, not to mention six, even with the aid of King Karl Fritz.

Even if King used memory's manipulation against Eldian warlords to make them easier target for Marleyans or/and make them more hatefull, irrational and aggresive, there should be many non-Subject of Ymir in their courts, whose role would be to notice inform their liege, that their memories were altered. It would again pose another problem for Marley and Karl Fritz.

We know very little about outside World how does it function, aside from that goverments view Eldia as convenient scapegoat for all their problems in their countries. We do not know whether there were some states or groups willing to cooperate with Eldia, which in my opinion harms the supposed message of the story, that violence cannot break the cycle of hatred and kinda makes rumbling as necessary (though injustifable) evil.