LabVIEW is a powerful tool, but as with all powerful tools, there is tremendous depth to it, requiring lots of study and experience to become fluent in it like you would expect a LabVIEW Specialist to be. Presumably, that is why someone would hire a LabVIEW Consultant. But, it is rare for a LabVIEW program to be stand-alone. It is almost always one component in an overall system.
The system frequently includes NI DAQ hardware, but may consist of bench-top instruments, and almost always includes one or more test fixtures. It is common for a system to include motors, load cells, hydraulics, valves, pressure and flow sensors, and similar actuators and sensors. Thus, having someone with a much broader background and a systems-level perspective can be very helpful. Often such a person is referred to as a Systems Engineer.
Besides being able to cover other engineering aspects beyond just being a LabVIEW Specialist, having an overall systems perspective adds even more value. By understanding the entire system, and the sorts of considerations that could be crucial at that level, a LabVIEW Consultant can take the context into account and develop a better user interface and a more reliable and robust system overall than a LabVIEW Specialist without systems-level background.
So, whatever you want to call the LabVIEW Consultant you are looking for, check for someone with substantial systems-level understanding. We find that having a strong Physics background is a good foundation for systems engineering because they have some knowledge of every engineering field and know to avoid most of the pitfalls. That is why we look for strong physics and systems engineering backgrounds in any LabVIEW Consultant candidates we would hire. We discuss Systems Engineering in more depth in our Full System Integration with LabVIEW article.