The stakes will be much higher in the second Union event. Farming an MLB Lilum will require 22 players reaching the max for individual PP. If nearly every player in the guild isn't striving for max rewards, you likely won't be MLB'ing your's. My suggestion is to look for Unions filled with players that have MLB SSRs for elements they don't main (weapons) or eidolons that aren't in their main team. If they don't, their commitment during Union events will be questionable. Not everyone is committed to MLB'ing SSRs they probably won't use; you need to find the type that are.