This entire question is made up of spoilers from the entire story, all the way to the final manga chapter of Attack on Titan.

So, in the final chapter of the manga Eren appears to use the abilities of the Founding Titan to influence Dina (as a pure titan) away from eating Bertolt. This is enabled by Eren's ability to perceive the past, the future, and the present simultaneously, and use the founder Ymir's power while in the Paths. I'm confused as to the limits this ability, given that there are SO many different things that he could have done to more effectively resolve the situation and achieve his goals. For instance, couldn't he have just directed ALL of the pure titans away from Shiganshina District altogether? Or have stripped Reiner, Bertolt, and Annie of their shifting abilities just before they attacked in the first place? Or even started the rumbling then and there if that was truly his end goal at this point in the story? I'm curious if there is some sort of supported explanation that would prevent him from doing so. The fact that he was able to influence Dina at all (and was thus able to influence events from his current position in non-linear time) makes me wonder what he was capable of, and I'm not sure if there is a character motivation that would prevent him from doing any of the above as an alternative to what we see happen, if he was able to. He could have saved his entire family, all of his friends, and still destroyed the entire outside world just like he wanted when he first started the rumbling.

The way that time works in the series is a little messy, what with the retrocausality paradox that allows Eren to cause a lot of the events of the story using abilities he gains through... causing a lot of the events of the story. Even so, assuming there is only supposed to be one immutable timeline, I feel like it still makes more sense for it to have just diverted very early on with Eren using the founder abilities before the story even begins. How this would be explained... I don't know. All of the events of the story need to have to have happened already for Eren to get to this point, but if getting to this point is what caused the events of the story to happen (saving Bertolt by influencing Dina, influencing his father to steal the Founding Titan and transfer the Attack Titan in the first place, etc.) then that seems to enable some hand-waving anyway. Is this just a bit of a plot hole to me, or am I just fundamentally misunderstanding how time and/or titan powers work in the setting?

So, in the final chapter of the manga, Eren appears to use the abilities of

the Founding Titan to influence Dina (as a pure titan) away from eating Bertolt.

This is enabled by Eren's ability to

perceive the past, the future, and the present simultaneously, and use the founder Ymir's power while in the Paths.

I'm confused as to the limits of this ability, given that there are SO many different things that he could have done to more effectively resolve the situation and achieve his goals. For instance, couldn't he have just

directed ALL of the pure titans away from Shiganshina District altogether? Or have stripped Reiner, Bertolt, and Annie of their shifting abilities just before they attacked in the first place? Or even started the rumbling then and there

if that was truly his end goal at this point in the story?

I'm curious if there is some sort of supported explanation that would prevent him from doing so. The fact that he was able to

influence Dina at all (and was thus able to influence events from his current position in non-linear time)

makes me wonder what he was capable of, and I'm not sure if there is a character motivation that would prevent him from doing any of the above as an alternative to what we see happen, if he was able to. He could have

saved his entire family, all of his friends, and still destroyed the entire outside world

just like he wanted when he

first started the rumbling.

The way that

time

works in the series is a little messy, what with the

retrocausality paradox

that allows Eren to

cause a lot of the events of the story

using abilities he gains through...

causing a lot of the events of the story.

Even so, assuming there is only supposed to be one

immutable timeline

I feel like it still makes more sense for it to have just diverted very early on with Eren using the

founder abilities

before the story even begins. How this would be explained... I don't know. All of the events of the story need to have to have happened already for Eren to get to this point, but if

getting to this point is what caused the events of the story to happen (saving Bertolt by influencing Dina, influencing his father to steal the Founding Titan and transfer the Attack Titan in the first place, etc.)

then that seems to enable some hand-waving anyway. Is this just a bit of a plot hole to me, or am I just fundamentally misunderstanding how

time and/or titan powers

work in the setting?