Farah and smith are different players, really. Smith is excellent with the forward pack he has because he keeps the roll on going so well, keeps the side going forward, whilst also having a deft passing game and an excellent kicking game out of dummy half. Farah is more creative, however, more likely to pull some genius out of the hat, and doesnt need forwards to be as dominant. His one weaknes is probably his delivery from dummy half, just isnt quite as good as Smith's.
Both excellent players. Be interesting to see how Farah goes if he gets another shot at origin