Yes, I do suppose that is true. They did a sort of piss poor job of maintaining the structure of the original Rocks the 80's disc, but I'm sure it'll all check out. I've made my own discs of GHI and GH80s and and currently working on a GHII disc now.
EDIT: Only mine have proper set lists, so all the songs are in the same order and tier as the originals, unlike this disc you've found.
EDIT2: Oh, I get it. They shoved 80's and GHI on to the disc, though they must have had to cut a few songs out because there aren't enough places for all the songs on the two discs.