I've been wondering for a little bit about how Equestrian's fight aside from the slap right's we saw in the season 5 finale. How would a horse develop a hand to hand combat style?

5838170 Try watching Canterlot wedding again. The montage in the middle was pretty good material.

In my mind, Pegasi use something like Kenpo, Earth uses Kung Fu, and Unicorns would use a magical equivalent to Aikijiujutsu

Also watch dressage videos IRL. Dressage moves are taken from cavalry attack training exercises. MLP ponies are a lot more flexible, but you can imagine some devastating pony-exclusive attack setups coming from those.