Finn is somewhat underprepared. Poe is only trying to help.

“Can't kriffing believe he sent a Naboo to kriffing Tatooine,” Owen says, too loud, but—they're in the middle of the wilderness. There's no one who’s going to hear him except the Force, and if it does hear him, he hopes it turns around and beats some light-bedamned sense into Obi-Wan Kenobi’s skull. In his lap, fully entranced by the corner of the blanket Owen has him bundled in, Luke coos, beams, and flips his tail. The fancy, flowing, colorful fins slap Owen’s thigh, and he sighs, tugs the bottom of the wrap down to hide as much as he can.

Stone was a solid weight, a shield for the Guard as much as he was able, built from the stone that he was named after. And if he didn’t have that, what did he have, in the end?