So instead of halter... what about obstacle shows. 

Instead of going off the BS, the horses could be judged on their skills and personailty like with careers.

Say a horse that is unperdictable would have a harder time as would a timid horse. But as the skills increase such as Tolerance and Patience, the horse would score slightly better, but still have that unknown factor. 

A horse that is a Loner and Lively would be harder to handle till the Communication goes up. Cause they think they alredy know it all.

Just a idea and something different. Figured skills and personality are already used for careers, why not make it something that is multi purpose.