I have a network that uses the 192.192.192.x network address for their private network. It looks like publicly those are IP addresses that are assigned in Taiwan. I don't think they do too much business there, so it shouldn't "impact" their work.
My question: Is there any RFC information or any other networking articles for best practices that I could present to justify changing the network to a real private IP class network?
RFC1918 outlines the IP space that should be used for private internal use.
It sounds like you already know this, but users on this network will not be able to communicate with any devices that are on the real 192.192.192.0/24.
Also, as @voretaq7 points out in chat, your registrar might be none too pleased with you using public IPs that aren't yours.