The terms "scenes" and "chapters" are defined fairly loosely and can be used interchangably--the difference is the medium. There are many ways to build chapters/scenes. The instructions in the StoryGuide are one way. Examine the suggested chapters in the Novel Structural Template to see another.
Chapters/cenes can be defined in many different ways and therefore there can be many different "appropriate" numbers of them. Personally, I think you need as many (or few) chapters/scenes as is necessary to tell your story. You can wing it and do it by "feel," or you can use some sort of "logical" approach such as following the structure template, the storyweaving suggestions in the StoryGuide, etc. There is no "right" or "wrong" number of chapters/scenes.
With that said, I'd like to point you toward a resource you might find helpful - Armando Saldana Mora's book Dramatica for Screenwriters. You might find Section 5 of particular interest. It is called: 3 Acts, 16 Sequences And 48 Scenes—How To Get The Complete Plot From Dramatica. I think you'll find it easily readable, highly entertaining and surprising informative.