The phrase "a fluid set" is correct and usable in written English.
It can be used to describe a collection of items or concepts that are not fixed and can change or adapt over time.
Example: "In the context of modern art, the definition of what constitutes a masterpiece is often seen as a fluid set, evolving with cultural shifts and artistic movements."
Alternatives: "an adaptable collection" or "a dynamic group".
Thatcherism was never a fixed but always a fluid set of attitudes and inclinations.
It's hard to look at how you affect development with such a fluid set of assets roaming around the countryside.
Not all of these decisions will be based on evidence of harm or illegality, but on a subjective interpretation of a fluid set of rules.
In its inherent disorderliness, strategic opportunism requires a great deal not only from the senior manager but also from the manager's subordinates, who must be able to tolerate working with a fluid set of agendas.
This new secrets exchange has its own set of bankable stars and one-hit wonders, high-rolling power brokers and low-level scammers, many of whom follow a fluid set of rules that do not always comport with those of state and federal law, let alone those of family or friendship.
External proportional control (an input signal between 0 and 1) is in effect as long as a fluid set point temperature is not exceeded.
Literature helps develop these skills through the novelist's ability to capture a complex, fluid set of social relationships.
Today, what exists instead is a constantly changing, fluid set of relationships between London and Edinburgh, confused by feeble constitutional wheezes that arrive too late.
A fundamentally more fluid set of interactions between the edge and the core means everything has to work together better.
Demographic trends reveal an increasingly diverse and complex family life and a more ambiguous and fluid set of categories traditionally used to define the family (Cherlin, [2010]).
Rajagopalan, R., Vaucheret, H., Trejo, J. & Bartel, D. P. A diverse and evolutionarily fluid set of microRNAs in Arabidopsis thaliana.
