Personally, I believe that a strong leader allows for opinions that are contrary to their own. In fact, I have at least one employee that disagrees with me on a regular basis and I foster that contrariness. I am not infallible and certainly do not know everything. I do not want “yes (wo)men”.
As a leader, part of the role is to understand the larger scope of things and the long term strategy behind decisions. In really comprehending this, you NEED people who are contrary to your opinion, your work style, and your thought patterns. This allows you to round out areas that you’re blind and avoid making a decision that is wrong simply because you don’t have the visibility.
I equate it somewhat to having a passenger in the car who happens to look out your side-rear window and yells “Look out!”, even though you’ve been checking all of your mirrors. 
They have a different vantage point that is more focused (only looking at the side) where as you are responsible for all aspects – front, back, and both sides. You need to trust that someone who is focused on a specific area might have a better view, better information, or better knowledge about what’s occurring in that arena.
This, however, does NOT mean that a strong leader allows an individual to derail everything or to argue with everything. At that point, you have a backseat driver in your car and should probably ask them to tone it down or step out. There is certainly a fine line between constant disagreement with your employee and strong leadership accepting the varied opinions of your team. If your employee is constantly diverging from your vision and direction, there comes a time when you (and they) need to make a decision on whether or not the individual belongs on your team.
In the case of my employee, s/he agrees with the vision; s/he agrees with the direction. S/he just doesn’t always agree with my direction and is willing to stand up for what s/he believes. Once the decision is made and the direction is given, s/he accepts it and moves on. There is true mutual respect and it boils down to a simple fact: I have the final say. Someone has to.
That is how your, as a leader, should allow your team to bring their strengths to the table.