Theatrics? This sounds like you saw Eren's behaviour as something he affected as a kind of performance. I thought it was rather genuine... May I ask why you thought so?
I stand by my use of the word “theatrics”, not because I think he’s insincere, but because Eren’s strong emotional reactions are often accompanied by a dramatic flair. It’s precisely why Hange didn’t coach him before his military trial in chapter 19. They knew he’d deliver by nature of who he is.
Eren would’ve said or done anything to keep Armin alive. I honestly don’t think he believed half of what came out of his mouth. He was grasping at straws, throwing out any argument in hopes that one might stick. Like if Levi had said “Erwin has six toes”, Eren would’ve responded, “BUT ARMIN HAS SEVEN AND THEY NEED TO BE DIPPED IN THE OCEAAAAN!!!!!”.
If it had been any other character, I could’ve dismissed Eren’s behavior with a shrug and an eye-roll. But you need to understand that Erwin Smith is my guy and to see his lifetime of extraordinary accomplishments compared to those of Armin Arlert’s made me feel actual revulsion.
As I’ve said before, I don’t hate Eren. It is my opinion that at this moment in the story his behavior was awful, but also very human and understandable (and also very theatrical lol). You are welcome to disagree.