Hard work can take you far but being smart can take you anywhere. That is the difference of those two. Hard work can give an opportunity for us to afford all the things that we need but if you will become smart then you have a bigger advantage because you will see things in a bigger picture and you can easily adjust and implement strategies because you understand the game better than anyone else in your competition.
From my experience, I would say that both of them are important and it is not right to say that one out of the two is better than the other (here the OP is prioritizing smart investing over hard work). I would rather say that smart thinking acts as a multiplier over the existing hard work. Perhaps it will be better if I could give an example on how this works.
It works like this: first lets classify the individuals on a level from 1 to 10. We have 3 guys. The first one is a lazy guy, with rating of 1, second an ordinary guy with rating of 5 and third a hard working guy with a rating of 9. Now lets once again classify them based on the smartness scale from 1 to 10. The first guy is very smart, with a scale of 9, and the other two are average, with rating of 4. And this is how it works:
Individual A: 1 x 9 = 9 net points
Individual B: 5 x 4 = 20 net points
Individual C: 9 x 4 = 36 net points
Here the maximum points go to someone who is both hard working and smart.