I think Okazaki will be a key player for us, no matter who plays in front of him, Vardy, Slimani or Ulloa.
I know some people on here deride him as a bit of a joke, but for the first 60 minutes of a game I look upon him as our offensive version of Kante.
I'm an Okazaki fan too, what he adds to the team is something beyond his own abilities. He's a vital part of our shape. Yes he falls over, and is a master of the pained expression, but I'd not be without him.
I don't think we see him much beyond 60 minutes to know how effective he might be in the last half hour!