How do I mitigate 'alpha playing' in Pandemic?
Of course this can happen, but the expectation is that all the players help contribute to finding solutions to the current problems.  While you might see one path, someone else might see another, that happens to be better.  Having multiple people working on the same problem from different perspectives generally provides better results.  Kind of like crowd sourcing.  

I tend to like games where I win or lose entirely by my performance, but I play games with people that like cooperative games like pandemic and Legendary. When we win it usually takes all of us thinking through the possible scenarios and agreeing on a course of action.  

In your situation, if you tend to be the direction of all the movements, then I would suggest people don't share their cards by default, giving them an angle to make suggestions from.