They have no additional content besides the games themselves, they're just packaging names. Endless Universe was packaged to run without DL because the company in question didn't have the rights to include DL at the time, as I understand it.
While DL is a very different game, generally speaking, if the options were reversed, I wouldn't worry too much about only getting DA and TA.
However, in your situation, it's a no-brainer: All 3 for that price is a steal.
