As a practical matter, how does that differ from warming the horse up by walking, checking for straightness, turns, going to a trot, checking him in turns, transitions etc for responsiveness, etc?
For example: CONTACT.
What does that mean? Contact with the horse's mind? Contact thru the bit (or halter & reins if you aren't using a bit)? Response to contact with calf and seat? And regardless of which of those it is, when would anyone ever ride a horse without contact - unless contact refers only to a bit?
When I warm up my horse with a rope halter, I want interaction with his mind, and response to my inputs. Is that contact? If it is just the bit, then wouldn't every English rider ride with some contact all the time?
In what sense is it a practical list that helps you get the horse ready for the main event?
I suppose, but I think we're talking more physical here- Like I said I have never heard of the German training scale, but if I had to put those in order, that would be mine.
As soon as I get on my mare, I ask for a forwards walk, a long and low head WITH contact, suppleness comes from lots of transitions and speed differences within the walk (slow it, forwards, medium) in which there comes the collection and relaxation. As I said to gypsygirl, straightness for me isn't so much straight for riding a whole school without falling out, its being able the horse being able to balance on its own without me holding it up every step of the way.
I would say its practical in the way it gives you what you should aim for, before you move on to the next too soon, and have problems later on. As in you can't move on to collection, if you don't have connection. And to answer 'when wouldn't you ride without contact' it could be a training scale whilst teaching someone to ride, and until they've learnt the basics of contact. In some respects you could ask what time scale does the training scale have in conjunction to rider and horse training.
I really like the 'connection' with mind as well as bit though, I didn't really think about that one!