Stable controller IDs only really work on Windows, but that's not the problem here. SDL isn't detecting any joysticks, which normally means the kernel didn't recognize them. (Steam doesn't use the kernel services, IIRC, so it seeing a controller doesn't mean anything else on Linux will). On Fedora that means you have to install the kernel-modules-extras package to get all of the controller drivers, I don't know what the situation is on Arch (OG runs Arch I think? Maybe he knows).