Is Mike Smith the answer for our Defense?

I love love love the fact that Mike Smith had brought an exciting,  aggressive and new scheme that our players are ecstatic about playing in. My question and concern is. ...and i really want to hear people's take on this.  Because of smittys success as a head coach and when he has success here in Tampa. Will Smitty be here one year and move on to be a head coach somewhere and leave our players having to learn yet another defensive scheme next year!  Are the days where we can have a defensive coordinator for a number of years over? Just makes me nervous.