Why the question?
The Native has been around the longest and is into its 5th generation since it was first introduced around 1997. The Sage was 1st released in 2008 and the Chapparal in 2011; neither has seen any generational changes yet.
While they superficially look the same but they have different ergos and offer different scale/lock/blade combos. Different strokes for different folks.
The Native 5 is the most diversified model in terms of the types of scale/blade materials offerred but it only comes w/a back lock. The Sage/Chapparal come in more limited blade/scale combos but are offered w/different locking mechanisms, including a compression lock if you prefer it.
The only one of the 3 that I've ever purchased/carried is the Native. After buying my 1st Native, which was a Gen 5 PE S35VN G10, I never had any interest in buying a Sage or Chapparal. I decided to expand my collection of Natives later.
Lousy photo but this is my collection of Gen 1, 2, 3, 4 & 5 Natives.
I don't often carry any of my Natives but, if I do, the PE S35VN G10 Native 5 (3rd from the bottom) is the one that I will usually choose but I also have an extra "user" Gen 2 PE S/S Native (3rd from the top) and an extra "user: Gen 3 PE FRN Native (5th from the top) that are not pictured that I can also carry.
Still looking for a PS/FRN Gen 3 to complete my collection of the Gen 1-4 Natives.. The Gen 4 only came in PE/CF. Too may variations of the Native 5 to bother collecting. So, I'm happy w/just the Native 5 PE S35VN G10, PE S90V Fluted CF and the PE S35VN Fluted Ti (the bottom 3 in the photo).
Was planning to sell the Gen 2/3 "users" (which were subordinated by the better versions pictured) but I just haven't gotten around to it yet.