[Q] CWM Recovery Questions

I have a SGS2 (GT-I9100G) and have it rooted and a custom rom flashed. I'm still slightly confused on the CWM recovery installed. I was under the impression CWM was installed when I rooted it with SuperSU and then loaded a CWM zip. However now I have flashed a new kernel and the CWM recovery has changed. So my question is, is CWM installed in the Kernel? Also can this be upgraded without flashing the kernel? Lastly, I have version 6.0.1.2 however on the CWM website it lists 4.0.1.5 as the latest version!? And CWM Rom manager lists this as installed...

All in all CWM confuses the hell outta me! Any clarification would be much appreciated :)