I don't think anyone's going to disagree when there are suggestions that our system can be more efficient. But the thing is that we implemented the system that we knew would at least be partially effective, because partially effective is better than what we had before: nothing at all.
I'll bring your proposed methods to the Devs. Hopefully that will be a viable solution, but remember: things always work well in theory, but not always in the real-world. And until some philanthropic anti-cheat genius helps share his knowledge of cheat detection, we'll have to keep experimenting until we get something that works.