The confusion probably comes from following the links in the post, rather than just downloading the actual file attached to the post.
The heroes mod is actually unmodified, but it is 1.5 and not 1.6, so if you just download the latest from the heroes thread, you'll get the wrong one. The CB mod is the one that's a little nonstandard and might cause weirdness if it doesn't match up.
You shouldn't need winrar to use that attachment since it is in ZIP format. Windows XP can read ZIP files without any extra utility at all. (Macs won't work because of the dominions bug, and if you have Linux you are expected to know what you are doing on your own
)