The problem you have, is motors tend to be high current, and when you have high current, that is when you get voltage drop. And as you increase the conductor length, you increase the drop. So motors at the end of the chain would run slower than the ones at the start. I think your professors have valid concerns, because you'd have to account for situations where possibly two or three motors are running at once.
One way around this, would be to jack up the voltage, have a high voltage bus, then each module has a DC to DC converter dropping it down. This would mean the supply was high voltage low current, but each module could be low voltage high current. It also means each device is regulating it's own voltage, and less susceptible to drops in the supply line. The down side would be more wasted power, as each DC - DC converter, even though highly efficient, would eat some power.
Basically, the higher a voltage you can have, the lower a current you can have, and less loss in the cabling, for a given power output. You should also consider the safety side of things too, because as you increase voltage, you start to stray into the safety areas, where you would have to mitigate any risk of someone touching a high voltage line, and getting a shock.