[Richard]

Jeff, that last pic may not be a great example.

Normally equal pressures on equal discs result in no movement.

In the pic above the surface area of the disc on the left side is greater than the surface area on the right side because the diameter of the rod must be subtracted. So in the literal answer to your question about the picture the rod and piston would move as far to the right as possible if equal pressure is applied to the ports.

Reacting to post #29, there must be something else going on with ports and internal valving in the rear cylinder that is not evident.