While not a de facto faction, neutral units are mostly hired mercenaries that are open to temporarily join arms with any other faction's ranks as long as they can make a living out of it. Some are wandering adventurers, some various kinds of deliquents, yet they all seem to value money above any other motivation.
Many neutral cards can provide access to certain types of utility that each faction can take advantage of.
Some neutral units have a unique hire mechanic that allows you to use cards in your hand rather than pay their cost.
As they are mostly mercenaries, neutral units have access to mechanics that reward them for doing their job.
