No, the Vega and Cosworth Vega had the conventional 1-3-4-2 four cylinder firing order, and the Iron Duke wasn't any smoother than the 140 Vega engine. The roughness is due to the large displacement long/stroke architecture and simple rubber mounts. Those were BIG four cylinder engines for that era. Better engine mounting and the twin counterotating shafts that balance the four-cylinder's second order unbalanced vertical shaking force have considerably improved modern fours, but they will never be as smooth as a good I-6. That's why I rejected a 190E 2.3 16V in favor of the 2.6, even though "on paper" the 16V had better performance.

Duke