Board Thread:Questions and Answers/@comment-24452043-20161112081850/@comment-5101200-20161112145409

The Anur System was apparently at one point confirmed to be within the Milky Way Galaxy, so we can assume the same thing is true for Dimension 23. The Omnitrix starts out with all the DNA samples from the Milky Way Galaxy, so Blitzwolfer, Snare-Oh, and Frankenstrike were all there to begin with. Prime Ben just unlocked them by coming in contact with aliens of those species. It's kinda like how he unlocked ChamAlien, where the Ultimatrix said the DNA sample was recognized.

I think the real question is what events lead to Ben 23 coming in contact with a Talpaedan at one point to give him Toolboxx, considering they're from the Andromeda Galaxy. Could be a number of things, such as a Talpaedan enemy, Talpaedans having been from the Milky Way Galaxy in Dimension 23, perhaps Azmuth 23 went further with his DNA samples than Prime Azmuth, etc.