Must group norms conform to the organization's norms, and can the leadership of the organization minimize or change a group's norms? Are unions formed because of group norms operating within the organization's norms are rigid or unfair?

Q1 It is desired that group norms conform to the organization's norms so that organization effectiveness could be increased. At least it is expected that both are not working at cross purposes and others see them in confrontation with each other.
Leadership through its credibility and communication effectiveness minimizes differences between group and organization norm or change a group's norms. This is possible by convincing group that they will have advantage as group if they adopt new norms.

Q2. Definitely if there is no flexibility then chances of union formation are more. If management considers that group norms are not in confrontation to Organization norms and are very strong then if management is flexible enough to adopt of some of group norms then unions are not formed. Further if group has perception that Organization norms are unfair and management is not able to convince the fairness of norms for both organization and group then chances of union formation is strong.