Flow Regulation using a Pump and Flow Control Valve in LabVIEW

Hello everyone,
I'm not sure on how to properly regulate my actuators with my Labview program
I'm regulating Volume flow using a Pump and a Flow control valve, all of this through a numeric control, I can control both actors by giving digital signals through DAQ,
my pump can't go too low with it's RPM, at a certain point it won't provide steady volume flow anymore. In order to get an even lower volume flow, the Flow Control Valve starts to "close" in order to create resistance for the pump, the pump will remain at the lowest possible RPM while the valve is active.

I thought of using PID control to regulate the parameters, but my professor was convinced that the system is "too slow and sluggish" and I should instead just us (tabular values, so basically if the volume flow is set too low for the pump to handle like: volume flow = 0,4m^3/s ->Valve closes 10%)

I must say my professor isn't a LabVIEW pro just like myself and I'm not sure what to really do in this case, what do you all think would work better for this application and has anyone has a similar system?
I hope i provided sufficient information (pls dont make of me this is my first post)