Arduino setup with heaps of sensors/Paternoster

I have question regarding cabling and how many arduinos to use.
I have a plate with 4 sensor units, 1 on each corner. The plate has the dimension of 400x1200mm, but it might change in the future. The sensor units in front differs to the ones in back by that they have one extra motor, current sensor and voltage sensor and the two in back do have an extra potentiometer. The motor could peak out at 30Ampere @ 12v, however only one motor per unit will be running at maximum current at the same time, i.e total consumption = 30A.
On the front units I have 3+2=5 IO + 2+2=4 analog inputs and 2 interupts
The back units 3+1 = 4IO + 1+1+1=3 analog inputs and 2 interupts

The control hub has 4 analog input and needs to communicate with an android tablet, so I guess arduino leaonard will be perfect for this. The question is how to get the 4 sensor units to communicate with the control hub. Should I put one arduino at each corner of the plate and use the wire library to transfer information to the control hub. Which cable connector to use for such a transmittion of data? And which cable/connector to use for the power(30A,12V)?
Or should I just make a connector at each corner, minimum 12pins(vga connector) and a power connector(which one?) Then run the 4 cables to the control unit or run it to one corner and there combine it to 11+11+9+9+gnd = 41 pins connector to the control unit and a 120A cable to the power supply.
Attached is a eagle picture of the system layout.

What sort of current sensors are you using? If they are shunts, then the microcontroller that reads them has to be grounded to the shunt (otherwise you will get errors due to the resistance of the motor cables), in which case the easiest solution is one mcu at each corner. If they are isolated Hall current sensors, then a single central microcontroller may be an option.

Havent decided on any sensors yet, just figured out which sensors that i need. I just need to have some kind of current sensor to figure out if there is a mechanical jaming that avoids my motor to run properly.

Maybe the 50A version of then.

Ok, but should i have 5 or 1 arduino? and which connectors to use and cable dimmension?