Power supply for multiple microcontrollers connected via CAN

I am thinking about shifting my project from arduino to standalone atmega on a pcb. Currently I have a network of Arduino's connected via a CAN-Bus. The cable length between the modules is not long in total maybe 2 or 3m.

I am thinking if i can supply the power for each module from one source of 5V or if I should use a stronger power supply and provide each module/pcb with a voltage regulator.

Does a voltage regulator (like the one used on the arduino) improve the reliability of the network or is is simply unnecessary when i have a sufficiently stable power supply?