1. First, to cause soem kind of uproar, civil unres tor the like. My idea is that if they found out some way of doing what Zeke did to Ragako village, then they'll most likely go for it. Why? Because if that happened, it would likely make anti-eldian sentiments within Marley soar to new heights as well as remind the Eldians under Marley's control how precarious their situation really is; right now, they're deluding themselves by thinking that as long as they play loyal dogs to their masters and unerringly follow their orders, they'll be safe and the world will eventually stop seeing them as 'devils', but anti-eldian sentiments soaring to new heights would serve to remind them - or making them simply realize - that the situation isn't that simple...
For something like that to work I think it would have to be a pretty sneaky and schemy plan. If the Walldians tried to talk to the other Eldians, I think their first (and only) response would be to blow the whistle and call the Marley right away because they're just that brainwashed, and want to do anything and everything they can so that the Marleyans will approve (like lapdogs, as you said).
Like, the Walldians would have to somehow make the Marley commit a very big faux-pas, like revealing that they are (have always?) considered to exterminate ALL Eldians at some point, maybe when the Paradis mission was resolved.
That would be something that would HAVE to make the ghetto Eldians wake up and go
"
YEAAH- wait what, hold on a minute..."
Otherwise I think it would be a tremendous waste of their time to try and pull off something like that... UNLESS they somehow made contact with yet another revolutionary group.
If that were the case, I wouldn't mind at all seeing an "Uprising arc" taking place on Marley to overthrow them, winning over people little by little, but to be honest I don't think that's too realistic, then again we just don't know what the current situation is from the Walldians' POV.
2. Their plan is to strike at the Titan Shifters. They still are the Marley's greatest asset and the greatest threat the Eldians on Paradis faces. If they manage to capture one or two of them, that alone tips the scales somewhat in favor of Paradis's cause, and even if they only manage to knock one or two of them temporarily out of the game, that still buys some time for them.
Yea, like I said on the main thread, it would make sense for them to try and kidnap the new Warriors, because if you take them away, the others would be left with no one (worthy/trained) to transfer the powers to.
However, this doesn't really work because whatever happens in the future, needs to happen in Eren's remaining lifetime (3-4 years), and nobody knows how long Reiner/Zeke have left to live, so they can't simply kidnap the new Warriors, wait for the others to die and let the powers be transfered to unexperienced people. That would take years and years.
Trying to do something to another current Warrior might be a bit risky though, I don't know... If this was somewhat of a moderate operation, they could pull it off; if there are more people with Eren there, they could've easily followed all the shifters/Warriors to where each lives, and strike during night time at their own houses while they sleep, like drugging them/putting them in a vegetative state or something like that.
Marley would lose their shit if ALL Titan powers/warrior candidates simply vanished without a trace!
such as finding out the current state of things in Marley, the Marley's military strenght and so forth...
Logically speaking, I believe they already achieved that by interrogating the soldiers on the boats.
I mean, they sent 32 ships, and I don't think the Walldians would be dumb enough to not make any prisoners. With 32 big-ass ships we can safely say that that's at least a few hundred soldiers.
All they would need to to is interrogate them all separately, and then analyze the info side by side and see what matches up and what doesn't.
