@eightpondfarm
It’s very interesting to watch other trainers and students ride but at the end of the day you can only evaluate what your own trainer asks you to do with your horse at that moment.
I expect there are complex reasons for the combination of rider and horse you saw. Number one is that for whatever reason your trainer does not want to be the primary horse trainer for that horse and owner combination and I expect has good reasons which she is too diplomatic to share. It is possible the horse is green, or trained incorrectly, or has behavior issues. It’s possible the owner is an over horsed beginner or a difficult personality or on a tight budget.
As far as how the younger trainer rides, you dont know what they were trying to achieve. Maybe they were trying to get the horse to open the poll but he wouldn’t. Maybe they were fighting a horse trying to bolt or buck. Who knows.
It’s possible as well that your trainer does not entirely approve of young trainers riding and is trying to fix her bad habits.
None of this has any bearing on where you are in your own dressage journey. If every single rider who had come up through your trainet has serious faults that’s a red flag. But in this case, I expect younger trainer got all her experience elsewhere and has hooked up with your trainer since coming to this barn, for mentoring a likely because they recognizes what she does well. I would not however necessarily evaluate her as a pure product of your trainers system.
As far as trot and canter work, yes obviously as your training progresses you do a lot more of that. I do think walk is under rated as a way to do basic training. But obviously you also need to school extensively at faster gaits too. Dressage relies heavily on trot, like jumpers relies heavily on canter.
A few years ago when I had daily care and riding of an aged school master who needed to be fitted up, my routine evolved to this. About 10 to 15 minutes going through all the walk lateral work from flexion to half pass both directions. About 10 minutes going through all the lateral work again at the trot. The next 15 or 20 minutes we would do canter patterns, collected to lengthened trot transitions, and true extended trot of she was feeling really good. We did canter half pass and a couple of days did a loose but real canter pirouette. Then cool down. She really liked a 45 minute session.
Her physical issue was topline loss causing her to fall on the forehand so all my work kept in mind encouraging her to lift in front. She was a real energizer bunny and riding her collected canter was a dream, she loved canter, so I had to keep the two of us from wearing her out while building fitness.
I ride all kinds of impromptu bends and half circles etc off the rail feeling what the horse needs at that moment that day, and also lots of change of head position and transitions within gaits. There will be days with my non-dressage talented Paint that we trot and canter on the trails and only do walk lateral work for 15 minutes in the ring. Her issue is warming up enough to be forward enough to school.