Armin! Erwin just kills everyone.
Erwing for sure
its not that Erwin kills everyone, he just knows that it'll take countless sacrifices to achieve their goal.
He has barely had any development in the manga and his only role is being a commander. Even Hanji Can take his place.
barely any development? the dude has too had many developments. since the beginning, he's been behind every plot every since they got their hands on Eren when he first turned into a titan. he was behind the plot in capturing Annie (along with Armin who revealed that it was Annie), as well as the plot in bringing out Reiner, Beholt, and Ymr identities who were also titans like Annie and Eren (also with the help of Armin). he was also behind the plot in overthrowing the puppet king and organizations. he was able to bring in technologies and inventions that were being kept from them because of the kingdom. he wasn't just a commander, he was a mastermind about everything. he's done many things in the story that you should give him credit for. you can pretty much say Armin is a mini version of Erwin due to the fact that he's also strategic and knows of the consequences in those plans.
Armin is an extremely clever, valuable fifteen year old, but Erwin is smart, strong, powerful, mature, and wise. He's an excellent battle strategist, and politically well-positioned. He's the only character who could have planned and successfully executed a coup d'etat, and he's the only character who can save the Survey Corps.
Which one is more clever? Armin or Erwin?