It is important to understand that all fans are not created equally. For example, many ceiling fans sold in discount home improvement stores are more for looks than performance. An engineer friend of mine calls them decorative noise makers.
While I have not found any detailed specifications for the 20" Extreme Garage fan from Menards, I do notice a few key things about the fans that lead me to believe they would fit into the noise maker category. First of all, blade area and pitch are vital to seriously move air. A Turbo fan from Sullivan's or even some of the quality competitor fans are 24" in diameter. That's 20% more diameter.
Secondly, while the Menards fan has 5 blades, they are significantly smaller in shape. The larger surface area of the Sullivan's fan blades can move more air.
Third, the 'pitch' or angle of the fan blade makes a differance too. Performance fan blades like airplane propellers are engineered to move air. I'd hate to fly on an airplane that would not have engineered blades. Than again, it might actually be safer as lack of enough air flow would never get you off the ground.
Finally, the speed or revolutions per minute of the flan blades also affects the air flow performance. The Sullivans fan is going to have significantly more rpms than the Menards fan. The Sullivans fan has a 1/2 hp motor versus a much smaller horsepower motor in the Menards fan.
While theoretically, your three fans combined could move a significant amount of air at a lower installed cost, I'm seriously questioning the ability of those fans to move enough air to equal what a quality fan can move. Sullivans promotes air velocity as the key to growing more hair. Air velocity is the speed at which the air moves. If you've ever stood in front of a Sullivan's fan when it is running, you'd lose your hat in a flash and you would quickly tire from the amount of air that is pushing you. These fans seriously move air.
I have seen fans like the Menards fan used at fairs for blowing air down on hogs or sheep to keep them cool. Take a look next time you are at a fair where these are used. They don't significantly move the wood chips that they are blowing on. However, if a Sullivans fan would be used for this application, you would not see any wood chips in below the fan.
Note: I'm not a paid advocate for Sullivans or the manufacturer of their fans. However, I am an ag engineer by trade and have worked in the rural utility market for 24 years.