Fan fiction idea! Opinions?

I've been doing some thinking. Ever since my old article Of Land, Spirit, and Stars came to a stop, I've wanted to write something completely new. Now, I have an idea for an article, and I just wanted to get your opinions.

In an unexplored part of Equestria, there live ponies that are completely secluded from the world outside their borders, and somewhat secluded within them, too. The land is ruled by a monarch who has only one law: Once a pony has their cutie mark, then they can only interact with ponies (besides their family) that have similar talents to their own. This way, order could be maintained. This is the only way of life that they have ever known. However, when the ponies are threatened by an outside force, they must abandon this rule, and join together.
(I hope I explained that well. I'm not too good at explanations or summarizing. XP)