different maps should work fine
get a mpq extractor
extract 1-2 campaign maps
examine them to learn how did they do
load the demo-campaign out of the campaign path [X:\Programms\Warcraft3\Campaigns or whatever], it is unproctected and there you can see how to create game chache and so on. + rep if i helped you
That tutorial tells you to "create a game cache as ANOTHER FILE with w3v format" which has nothing to do with what you have done
Just do what tutorial says....