Grounding question

My boat has four batteries. Two are in the back hatch by the motor. These are the original two batteries that power everything on the boat.

I recently put two in the center console, using the wiring supplied from the factory. This wiring just had the battery wires that go from the batteries through the hull to the front of the boat where the trolling motor plugs in, nothing else.

Should the two batteries in the center console be connected to the two batteries in the back with a common ground ?