Current list of "No Detachment" costumes. DZ - Bazine Netal DZ - Benthic DZ - Captain Ithano DZ - Doctor Cornelius Evazan DZ - Ediro Two Tubes DZ - Hondo Ohnaka DZ - Muftak DZ - Rune Haako DZ - Tessek DZ - Unkar's Thug DZ - Viceroy Nute Gunray DS - Sim Aloo
So having a new detachment for those costumes makes sense (I don't know why Two Tubes would be 501st, he's a Partisan = fights against the Empire... but that's neither here or there for this discussion).
I would hate to see KC become a "catch all" for all DZ costumes. Then you'll run into the problems that the Bounty Hunter's Guild and Flagship Eclipse has. When something becomes too broad it's hard to get help. Looking through all the active build threads going on right now here on the KC boards it's pretty much always Tuskens and Jawas. Which is fine, that's what this site is for.
If this new detachment happens it'll turn into a catch all for cannon characters that are thugs and "evil" but not bounty hunters or sith. Those costumes need to go somewhere, better to start something new to house all of them instead of dumping them here.