Basically, if the Chinese not only take Ladakh, but invade Kashmir and Jumma and have success there (perhaps because Beijing orders reinforcements) would they not seriously impair the military capacity of the Dogra dynasty based in this region?
And without the Dogras and the treachery of Gulab Singh, couldn't the Sikhs have survived? It is my understanding that the Maharani did not initially want to have an Anglo-Sikh War, but Gulab Singh encouraged her for his own benefit. And of course, the Dogras betrayed the Sikh army during the war.