One of the biggest advantages of aluminum is that it is supposed to wear at the toe as the foot grows. Wear plus the added thickness of aluminum allows the shoe to develop a nice, graceful roll as the foot is growing. The wear compensates for the hoof growth, allowing the horse to move more consistently throughout the shoeing period. Shoeing show horses today is a dilemma for the farrier. On one hand, you have the very good principles that are laid down by the educators and on the other hand, you have to consider the kind of movement judges are looking for.
Bottom line is that the judges and the stopwatch determine how show horses are trained and shod.
The farrier's responsibility is to shoe for the judge, keeping as close to the principles of good shoeing as possible. Fortunately, balancing a foot serves both sides very well. What does cause trouble is the amount of foot some farriers take off in order to achieve a balanced foot. I have never had great success with overly short feet. Horses with feet trimmed to excess don't take a full, fluid stride.