Dude, not true. i only had to buy the first DOW and dark crusade and i got all races, even the IG.
You are talking about skirmish. He means multiplayer. Go play online, and you'll see what I mean.
if im not mistaken, you don't need to install the old DoW and WA . Just enter the original serials for tehm in Dark Crusade when asked for them.
LOL you are wrong you have to have DoW and WA then install DA and it will ask you for the serial keys of them both