A strange example but take the replicators from Stargate Atlantis. They were robotic entities that in the end took the form of the Ancients and built their technology much like them. However, there were some who differed from the central coding and wished to ascend to a higher plane of existance (As the Ancients did more often than not) since they saw it as the next technological jump. In the end a rift appeared in the group as the majority had given up on the ascension idea and some split off and went into hiding. They eventually were destroyed by the majority but my point is that they existed.
Yes it's a tv show and yes it may not happen in real life but we are not in real life and these are ALIENS we are talking about. Everyone goes on that Nomads ought to RP this way or that and not differ at all, simply because the Keepers appeared before others and so got to dictate the 'norm'.
Yes they may share their minds and be like a collective BUT they are not one entity. They are controlled by multiple brains, not an overall single one (If there was one that strong then humanity would already have been mindcontrolled by it) and so there are always going to be some form of differences.
