That could be a solution after a while, but especially with expansions I think it would be a bad idea. Music and graphics grouped after a while could be a good idea, though without a discount those groups will be expensive and people might not buy them for it. 2€ for a music of graphics DLC is nothing (it is the price of a discounted bag of chips after all), whereas a graphics/music group at 30€ is more likely to make you not buy it as a new user.
I just meant as a way to sort stuff on Steam. One of the times I was buying some CK2 stuff as I had not played it in quite some time, I missed one of the Expansion style DLC's and didn't realize it till the icons for our swag came out, as there was a code I didn't have.