Pairing Arduinos to one another?

Hello, im wondering if i could pair 2 Arduinos to the same code. What i want is one Arduino to have a motor shield, and the other to have a servo shield. I want to have one code for both of them. Essentially what im doing is building a Rover and i know my Arduino Mega cant hold a servo and motor shield. So what i want is a 2 in 1 thing. Any Ideas. I need to pair them to a third Arduino that will be a controller.

Servos don't need a shield.
Just connect Arduino pin/ground to servo in/ground.
And dedicated 5-6volt servo supply to servo power/ground.
That's easier with a Mega, since pins 22-53 are not covered by a shield.