About the horsenalities - I value the concept and definitely agree that horses are much more complex beings than many believe - mentally, emotionally, spiritually. But one won't see it until ready to accept this complexity and to be open for some very mind blowing discoveries.
The horsenalities themselves are a basic concept about the basic characteristics of different kinds of horses, but it is a very good start to begin understanding your horse - it really helped me with my gelding, who is a typical, 100% LBE. A challenging one for the first horse, if I may confess.
For example, our relationships changed upwards when I introduced more action and less precision at times in our routine, less routine and more adventures, also longer ropes and more liberty. He has opened up immensely and is visibly having fun with me - and learning in the process! - instead of being dominant and hard to motivate.