When merging minor factions, their ships becomes merging factions.

When Choir merges minor factions, these ships leaves visible, which could lead unwanted "encounter" with other major factions.

When I'm playing Choirs, I want to be exposed by other major factions as late as possible, and I think this is the biggest advantage of Choirs.

However, merging minor factions have risks for me to be exposed too early.