Wireless networking solutions for 160+ devices within ~1 metre area?

Hi!

I'm working on a device that uses 160+ stepper motors, each driven by an Arduino Pro Mini clone. Currently, communication between the Pro Minis occurs via a daisy-chained, wired serial solution. While simple to work with conceptually, this solution is a giant PITA when it comes to updating the code as we're required to take everything apart, individually re-flash each chip, re-assemble and re-wire everything.

I'm currently investigating the feasibility of running tiny wi-fi capable Linux boards instead of the Pro Minis in order to more easily update the software and remove the need for a lot of the wiring. That said, I'm weary that the WiFi protocol was not designed to run so many devices in such close proximity.

Is this a bad idea? Are there other more suitable/reliable kinds of close-proximity wireless communication? Are there other embedded wireless solutions that are more lightweight than running the entirety of Linux, that allow for swapping out software without re-flashing? Any advice appreciated!