Well, the main questions that bring up an agreeable species is how they would last in a pony society and what they would do? From what we've witnessed in the show, they are greedy, rude, grungy, and too diamond obsessed to be able to share much of anything (which might include space). We still don't even know what they do with the diamonds/gems or what do they eat? Why are they a completely underground race? What is their society like? The show has shed very little light on the subject so Diamond dogs are not allowed until more light is shed. :/ Sorry.