If you do everything quickly, efficiently, and study the corresponding area of the map in the editor, then Rowzkavalier's guide is not necessary after the first 2 weeks. At the stage after capturing two Inferno castles (in the cursed lands), there is no longer a need to study the editor.
But the battles are not easy, so the guide can be very helpful at almost any stage of the game:)
It's not necessary to kill Wendigo before he appears; I killed him later in the field, although the battle becomes a bit more difficult).
Almost the same with the Boss; Rowzkavalier killed him after he appeared (I did the opposite, before), but in any case, having strong walls is recommended.
The type of surface is easily determined by the game's soundtrack.