Yeah. That's exactly why I don't trust settings for this info, it's never standardized.
Please try a df with Terminal Emulator
with your device.
These sort of allocations are quite standard for Android.
You ought to see separate partitions for /system /cache /data and so on.
Android = embedded Linux + Dalvik Virtual Machine + apps that run in the Dalvik and call Linux services.
The standard Android/Linux allocations need to be there and the rest is just device and os-revision dependent.
You've underscored perfectly my earlier comment about the differences in the two approaches - hermetically sealed (HTC One) vs. sd-expandable.
For some segment of the market, having a sealed unit of sufficient size reduces the confusion and complexity.
With flexibility comes complexity and you have to be more careful to buy the model right for you.