Via Resistance and Yield Optimization

A macro requires a via connection between M2 and M6. The EDA tool can drop a single large rectangular via, or a 2x2 array of smaller standard vias. A small via has a resistance of 10 ohms. The large single via has a resistance of 4 ohms. What is the total via resistance for the 2x2 array, and which choice is standard industry practice for high yield?