Soulstorm, the final expansion of the first Dawn of War, features almost identical gameplay to Dark Crusade, with a few changes. Again, it has a very shallow campaign mode that consists of capturing certain areas on the map to win. What I don't understand about the Warhammer 40K series in general is why they've spent decades writing a massive backstory lore spanning hundreds of books. Because they never had the intention of making a story-oriented game that would truly reflect these. If your goal is story, I recommend you stay away from Dark Crusade and Soulstorm DLCs. Their story content is so superficial that it barely fills even a few pages, and their gameplay is frustrating and boring. You can learn whatever story they are telling by opening it and reading it on the Wiki page.