With highly decisive ARO options becoming more and more common (especially the likes of Fireteam enhanced Missile Launcher and Multi Sniper units) the need for truly top tier active shooting is becoming more of a factor. That makes the edge which Yu Jing pulls (admittedly, second to PanOceania but up with ALEPH and Combined Army as the next strongest) a significant element which shouldn't be overlooked. Why does it matter? Because in the Sectorial with overwhelming active turn firepower as its defining feature, NCA, there are few to no high quality specialists to exploit the fact that battlefields will be swept clear of opposition. Trading only a very little of that "edge" in return for substantially better specialist options makes for a strong balance. And that's the space Vanilla Yu Jing, ISS and (it certainly appears) Invincible Army sit in.