Obviously there is a bit of trouble in translating weapon combat over to the anatomy of horses, particularly sword combat. Generally, I use a set of rules of the weapons in Equestria and attempt to form realistic fighting styles based on their range of motion in the show.

Swords: For pegasi, regular arming swords are easily used by gripping with the wing, as we have seen then do so. Longer two-handed weapons, however, are only available to unicorns, since wings cannot reach together and use a longsword or greatsword's leverage.

The problem arrives at mud ponies and their muddy hooves. Horseshoes are essential in fixing this. Earth ponies are able to use swords by attaching a horseshoe to the sword. The ends are each forged onto the quillons, while the vertex of the horseshoe's loop is a part of the pommel. This horseshoe then attaches onto the pony's hoof, or another another horseshoe the pony is wearing. Like the pegasi, they cannot use two handed weapons since three hooves is the minimum to walk and use hoof work.

When describing fights, despite the difference in anatomy, I simply keep the bladework more or less in tune with what is true in traditional combat. Where I see a need to modify the details, I add it, but for the most part, I would describe the techniques the same way I would describe this (action begins at 2:00):

Thoughts?

6028783 One thing I would recommend would be to take a step back and look at the bigger picture. Writing isn't the best medium to present details in fighting. Sure, it's nice to have some action sequences, but you should be careful not to bore the reader with needless details, else they might just skip the entire scene or even drop the whole story.

Sorry for this intermezzo, but I just wanted to point at the elephant in the room. I'm sure you have it covered, though.

6028794
Of course not every detail, but it must be established how the weapons work at some point in the story, and when there is action it can go from "they fought" to "it was a rapid exchange of cuts" to "he hung his sword in a high parry, thrusting in as he broke the bind." Some fights don't matter, but when the story revolves around characters who fight, there has to be a way to show who the skilled fighters are and who the rabble are.

I know in the Game of Thrones TV series, a lot of times they use stories or threats to show a character's confidence and reputation, but sometimes a quick exchange of blows can show who is superior.