The more stages a turbine has, the more air volume it can move at a given pressure, and also can generate more pressure with each additional stage. The thicker the coating, the larger the opening in the nozzle needs to be. The larger the nozzle opening, the more volume of air is required to atomize. Also, the thicker the coating being sprayed, the more pressure it takes to atomize it. The thicker the coating material, the more volume, and pressure it takes to spray it nicely.

This is why the fewer the stages in the turbine, the thinner the coating being sprayed needs to be. No gun alone can solve this.

There continues to be advances made with all the difference types of spraying. For instance, when they came out with Fine Finish tips for airless, and later Fine Finish Low Pressure tips, it made Air Assisted Airless superfluous for many coatings, and overlapped into the area that HVLP turbines covered for heavier coatings. The first time I ever used a Fine Finish tip in my airless rig, I put my top end turbine rig up for sale.

There is no simple answer that covers it all. It's a complicated subject. The short answer is that you can't do professional, factory, or better quality spraying with cheap equipment.