Driftlands: the magic revival vs Nomads of Drifland

[topspeed2000]

I am confused as to the relationship between these two games. The magic revival appears to have been published first, but the expansion, the forgotten passage, seems to work for both? Also Nomads is free? Can someone break this down potato head style for me please?

[DNLH]

Not everyone were a fan of indirect control you have of your units in Driftland: The Magic Revival and asked for direct control mode. Devs decided against rebuilding the game to accomodate a more RTS style (fair) and instead provided Nomads mode for the base game, which cut out the building almost entirely and put a focus on leading a group of units in set scenarios. At some point they decided to give out this mode as a separate game instead (Nomads of Driftland). AFAIK, Forgotten Passage is just a mission pack for Nomads.