In the other room, the kids sound like they’re having an argument.

Ezra, in a demanding voice: “That’s an unreasonable request?! Give me ten reasons why that’s an unreasonable request!”
Me: “Hey Ezra? I think you’re making an unreasonable request there.”
Phineas: “No, it’s reasonable! I’ll explain it to him!”

After that they were too quiet to hear but it actually did sound like Phineas gave ten reasons (I heard Ezra counting) and that Ezra was (mostly?) convinced by his ten points. So I guess that was actually a totally reasonable method of conflict-resolution they were using?