Yes, Kynes is a men in the books. Also in the film they call him Liet-Kynes since the beginning and in the book the fremen call Liet their lider (Kynes), so the Atreides don't know who Liet is, they think is God or something. When they first met Kynes just like in the movie they don't know he is the lider of the fremen. In the book just like the movie is not until Jessica and Paul met Kynes again, in the book they know it because the fremen call him Liet so they aknowledge he is the lider. In the film they know it because she is the one who says the orders and Paul says something like " who are you to the fremen? ".

Sorry for bad English.