To see how (perhaps even how easily) your implementation(s) can be defeated, compile a simple implementation in a skeleton game, then offer it as a reversing challenge for multiplayer game hackers in communities like MPGH, UnknownCheats, ElitePVPers, OwnedCore, etc.
If I understand your code correctly, then what you've demonstrated here is a way to obfuscate values that will really only defeat basic game hackers who know how to do exact value scans in a program like Cheat Engine.
Either way, here are a handful of considerations for you off the top of my head (as a game hacker):
If coordinate data stays in the same memory address on the client, it doesn't matter how much you obfuscate it. All a hacker has to do is scan for changed/unchanged values and they'll find their way to the right value. You could create duplicate dummy data to mix it up a bit, but that's easy to weed through.
If the local player structure is the same as the structure coming in from other player data (health, coordinates, etc. all at the same offset) via the server, then a hacker can glean quite a bit of information by hacking what they can for their local player.
How good is your network protocol? If that isn't shored up, then a hacker can study inbound/outbound packets and make correlations to discover which bytes are related to coordinates. From there, it's just a matter of finding the sub-routine(s) that handle that data. If it's obfuscated data, then it's simply a matter of tracing code execution to find sub-routines related to de-obfuscation.
Advanced reversers don't need to rely on dynamic analysis to find their way to what they need initially. Between custom tools, scripts, etc., they can find their way to code segments of interest--all without having to worry about dealing with your obfuscated value whatsoever.
Suffice it to say, there are multiple ways for game hackers to achieve success--many times the ways of which have absolutely nothing to do with your expectations as a forward-engineer of how your implementation(s) will be targeted.