You do realize that all the termies cant fit in the land raider dont you, also two out of the three missions are objective missions so people will just kill the scouts and then you cant win. Also your not really making the most out of the twin linking ability with only one melta weapon in the whole army. Think you may need to go back to the drawing board with this one.
Well, the Chaos Space Marines have the chaos gods on their side, while the Space Marines have Games Workshop on their's.
So one has the most corrupt, twisted and souless entities in existance helping them while the other gets the chaos gods.