So the Fighter is (let's not get into an argument about whether the playtest *sample* character embodies this for you) the best pure combat class in the game. It is entirely focussed on combat.
The Rogue is a the best skill-using class in the game. It is balanced between exploration and combat, with a powerful situational attack based on the use of its skills.
The Ranger, I think, should be the best hunter in the game - regardless of whether that's urban, wilderness, whatever. It should be a class which is equally focussed on exploration and combat.
So the ranger is just a mix between a fighter (bow) and a rogue (tracking).
So why not remove the ranger (and all other classes like him) and allow free multiclassing between the big 4.
Or even better, finally switch to a true classless system like all other modern RPGs.