um.. I guess you never brought the 4th edition set then, it too had 6 missions, each increasing the amount of minis used each time while teaching the rules, and it had an online expansion with more missions to teach more rules on their website (later compiled as a book, which I own a spineless version of)
Now blackreach on the other hand for 5th ed, what a cop out, no missions, nothing.....
Do you have any gaming clubs near you, or friends who want to buy the game and want to be space marines, if so try seeing if they would want to swap the DA for the traitors....
And lastly, I personally never complained, I was just stating that ALL the box versions of the core games, if you worked them out points wise, they were all unbalanced from the get go, and I mean ALL core games they made....
Space Marine/Epic; WFB; BFG; WH40K etc.....