There seems to always be an ongoing controversy that Eventing Dressage is different from Dressage. How can it be different. The horse has to do walk, trot, canter and some lateral movements depending on the level of competition. The horse has to go on the bit and be responsive to the aids. The rider has to show that the horse is obedient, responsive and do an accurate test.
The horse has to have correct movement or there is no way it could do a Dressage test let alone do a cross country course and stadium jumping.
I teach many eventers to improve their scores. One rider in particular has gone from being out of the ribbons to being in the top 5 on a regular bases.
The more correct flat work that is done through Dressage training will only improve the horse not hinder it. Doing collection work will not hinder a horse on the cross country course but will improve it because the horse will be able to come back more on the hocks to negotiate technical fences.
Gone are the days of riding by the seat of your pants relying on a clear, fast cross country course and a clear stadium course to be in the ribbons. Unless the Dressage score is good and I do mean GOOD there is no way a competitor will be in the top 5 or even in the ribbons.
Maybe it's just me but it seems the people who are the most outspoken that there is a difference are the ones who just want to jump and do as little flat work as possible. And then wonder why they are not in the standings.
There is no difference between Dressage and Eventing Dressage.