2000 Volkswagen Passat water pump

Engine Cooling problem
2000 Volkswagen Passat 6 cyl Automatic 85000 miles

the ac stopped working and the car began overheating. Mechanic said fan clutch was weak. We replaced that. When he got car back together, then said radiator needed to be replaced and thermostat was sticking. I ok'd the replacement of both. Called back and said thermostat was ok but ac condenser was all plugged up and needed replacing. Once that was done, car was still overheating. Now he says water pump needs replacing. My question: could it have been the water pump all along and was there anyway of knowing that before we did every else?