Is there such thing as a horse using its back end too much?

[Ziggy_]

Its been pointed out to me that my mare overtracks in working trot. By the time we get to medium trot her feet hardly seem to touch the floor and she over tracks by about a foot on each stride. In walk she also has a huge overtrack and seems to be naturally very engaged.

When schooling I've always worked on getting her to work from behind, well it looks like its worked!! Now my question is, is there such thing as too much engagement? She is well balanced, not on her forehand and her rhythm is consistent. Is it something I would be marked down on at low level dressage competitions, and if so how would I rectify it?

 

[Silverspring]

So long as the engagement is mirrored in both her front and back leg movement you definitely won't be marked down at dressage. You are really lucky to have a horse that naturally over tacks in walk as this can be the hardest pace to teach for dressage. An advanced dressage horse would overtrack by 4 - 6 inches in working trot so I wouldn't worry about it.
Keep up what you're doing it sounds like it's working really well