If I may speculate, they would probably take people from LH to start the ops. Even though they have many people with experience on the 320 in SXS/SXD, I think setting up a long haul ops on a new aircraft type will be difficult without some help from outside.
Since the Eurowings probably is a way meant for LH to move the longhaul production to another lowcost subsidary, there will be plenty of laid off Lufthansa guys to do the operation
