That is correct. The 3.8 liter Ford V6 was sequential (trumpet like). You may be looking for something more trombone-like. Infinitely variable. One moving part. Minimum un-metered air leakage. Possibly vacuum actuated. Porsche used this set up one the new 911. They insist that is was only to...
The Ford 3.8 liter V6 from the mid 90's is another example. Don't let that stop you. It sound's like you have some good idea's. Keep tinkering. And keep a log book. You may have a problem years from now that you solved today.
Safety is the reason for the seemingly odd spacing on radiator fans and alternator vanes. It was designed to reduce the stop motion effect while using stroboscopic timing lights. The illusion of a stationary fan blade only centimeters away from the pulley/timing mark can lead to obvious hand injury.