I didn't mean to discourage you from doing the ramener with your horse. And I certainly didn't mean to discourage you from experimenting!
I'm still interested in how you cue for the ramener with Moe. I did it with Mucki once via hand target behind the chin for example. Mucki looks very pretty like that, because his conformation favours those exercises and soon it looked like I imagined a ramener. Still I think that it was not the ramener that you get when the whole body is collected. So I guess it's just a different exercise. But it is still very interesting to try - especially like you did to check what muscles are used
... as she uses, I think its called, brachiocephalic muscle. The one that is connected to the shoulder. So she is obviously still using her shoulders to pull herself forward.
I would not say that using the brachiocephalicus is a bad thing, or wrong when doing the ramener. Actually, I think it's quite normal, if you ask me. I'll go into more detail - maybe more than you want, so take what you like and forget the rest
The m. brachiocephalicus is used for lateral flexion, if it's used only on one side. If both sides are used, then it actually lifts
the head. You can see the muscle on this picture:
It's origin is the shoulder blade, from there it inserts into the upper arm, as well as to the back of the head. If this part is contracted and the shoulder is fixed, then it is lifting the head. If the head is fixed though - by use of the ventral muscles, like the sternocephalicus for example - then this muscle, in combination with other dorsal muscles, is actually doing exactly what you want for the ramener position: it shortens the neck and takes it back.
Like with every collected move, this can only happen when the dorsal and ventral muscle groups work in accordance. So, in my opinion, this is where working in movement can be beneficial. I believe that in movement, collection - even if it is just minimal - comes very natural to the horse. Stationary, it would require a lot of pent-up energy, or training, to get into a healthy and natural collected state.
So if you walk in a slightly collected walk for example (short, but with energy), and then halt and ask for ramener, I believe you would get far better results, because it is done in an intuitive and natural collected way. That way, you could even train the muscles required to keep collection for longer periods
And furthermore, it's an excellent preparation for the School Halt