If somebody lists all the combinations with 100% accuracy, I will confirm it! 
UPDATE 1:
Upping the stakes.
Anybody that guesses the combo names correctly will receive a copy of Forgotten Gods upon release! (A winner has been found!)
UPDATE 2:
Alright, it is the dawn of the second day before the third day of the first week of this competition.
We do not have a winner yet (though some of you came tantalizingly close!).
I shall now narrow down your predictions.
Are you ready?
Soldier and Oathkeeper is…Warlord
It is the dawn of the third day before the fourth day of the first week and…
WE HAVE A WINNER!
Whispers from the eldritch realm had come to Evil_Baka in a sleep-deprived state and offered the true answer. The forgotten gods are pleased! You have earned a key upon release of the upcoming expansion!