In the old days, Suntour did not directly 'Cascade' technology down the ranks of their offerings. Cyclone was their top group in the early 70's. When they came out with a 'better' group, it became Superbe in the mid-70's and stay there until about 1981 (and Cyclone remained virtually unchanged as their 2nd-best group). Superbe Pro came out about '81 with some new new twists (better). Superbe, again, basically unchanged from '76 became the 2nd best, and Cyclone, also basically unchaged, became the 3rd best. All this went out the window with indexed shifting in the mid to late '80's, with suddenly Superbe Pro became their top groups forever with the new innovations cascading like Shimano. Also, they mixed up the names of their line, with the last of the Cyclone/GT/ARX names dissapearing in favor of numbers and new names.
Another note, Suntour did not really have a full 'grouppo'; i.e., one maker for everything, until the mid to late '80's. If you look at their offerings, some lessor items, like shifters, were common amoungst several levels of derailuers. In fact, I believe that their cranks, and certainly their brakes, and some other items were simply re-badged top-end offerings from other Japanese manufacturers (e.g. Dia-comps Royal Gran Comp brakes). This makes Suntour-spec'ed bikes before '85 or so sort of difficult to re-construct to OEM if you do not know specifically what they had originally. Indeed, I can recall at least 3 to 5 times that the brands we carried showed up with slightly different stuff that was in the catalog. With the differences on some older stuff simply beiong what name was cast/stamped on the part, this probably happened alot, and not just to the brands I sold at the time.
We could debate ad nausium as to where their approach to groups and not cascading technology was a good thing or not. It is not the point. In my opinion, the early '80's Superbe and Superbe Pro remain as the best shifting/least fuss/most reliable friction drivetrain..ever. I do not want to argue about this as it is simply my opinion. However, the only folks to make a crappier first attempt at an indexed system was Campagnolo. Suntour had it dialed in by about '89 or so (it was at least as good as Shimano, maybe better), but it was too late, and those later groups were not spec'ed much on new bikes and are now harder to find.