not really andy

as far as i can tell from what dazzle740 has said, they will be wired from the same switch (the only one that is at the bottom of the rad) and the same relay so they will still both switch on at the same time and draw the same current

usually you wire them separately so that you have the option of having them in series to get 6v each and run at half speed, or in paralel where they both get 12v and run at full speed.

that kind of strategy used to be common on A/C condenser fans (low speed when A/C on to aid condensing, and then full speed when a high pressure switch was reached to bring the pressure down), until PWM control came in where the duty cycle is variable between 0 and 100% to control the speed to whatever you want