We feel these special connections between Exotics are best when they are rare and a little bit hidden. That being said, we would like to add more of them to the game, especially for Hunters and Titans. Keep an eye out for the future!
It did seem a little weird Warlocks got the fun shit. What other families of Exotics are there though? Obviously, there's the Black Armory exotics, and I suppose the Fighting Lion and Eriana's Vow are a cute little thing.