... I still expect my horse to stay collected and their head to stay in the position I asked for.
I'll admit this drives me nuts. Western riding is not about collected gaits. It does require a balanced horse, and it does need a horse to 'gather' - to shift it balance to the rear for a period of time to free up the front for a swivel or sharp turn.
To me, western riding is NOT about what works in an arena, but what works in open country & ranching. A collected horse doesn't cover much ground. The thrust from the rear end is being used to support weight instead of create forward motion. I fully believe a horse moving like that could be a blast to ride, but it will also take forever to get from point A to point B.
A collected gait also limits where the horse can put its foot. That is fine in an arena, or maybe in a big grassy field. In much of the Rockies, however, the horse needs to constantly adjust its stride so it won't lame itself on rocks, cactus etc.
There is a world of difference between a relaxed trot and a collected trot. A collected trot is a lot more work for the horse. If you are going from A to B, and you want your horse to do something at B, then a relaxed trot will get you there faster & fresher. My mare will probably never give me a collected trot, but she has a very nice relaxed trot. It moves faster than a walk, is a pleasure to ride, and she doesn't tire herself out.
Historically, western riding has prized independent judgment from the horse. A horse that can take an injured man home, a horse that can follow the cow without constant input, a horse that will go "Boss, there is trouble here..." - those were valued. It didn't value a horse that needed to be told where to put its head - or its foot.
That level of control makes sense for dressage, because dressage isn't about covering a lot of ground and letting the rider concentrate on something besides riding. In dressage, RIDING is the point. On a ranch or trail, riding ENABLES you to do something ELSE.
Neither is right or wrong. They are just different. And there is overlap. When I needed to work on my horses flexibility (and that will be ongoing until they die, I suspect), I got tips from a woman with a strong barrel racing background. I later found the same tips in a dressage book. A flexible horse isn't western or dressage, it is just a good horse and good riding.
OK, rant over until I drink some more caffeine.