Sir, it's not possible for Pakistan to take away Ladakh through a land grab. Salami slicing/ "aman ka tamasha" accompanied by our naivette, yes.
I am not clear about what you mean buy the last two sentences. Mind elaborating a little?
I am saying if the Chinese opt for a shooting war, the terrain in Ladakh and J&K does not allow a 2 front offensive from Pakis and the Chinese at the same time. Pakis can do something only further south through the IB. That means we might have some troops tied up in the west to defend and focus on the Chinese side for offensive operations. So this threat of 2 front war is not as big as it seems after reading your post and looking at the maps.
Some points about a two front war - I'll focus mostly on the army part.
There are very few formations that have the option of fighting either on the Pak, or Chinese front. We can take on Pak without any of the Chinese tasked divisions moving out and vice versa.
We have the equivalent of 43 divisions (taking 3 independent brigades to be 1 division). China can deploy at best 13-14 divisions (which us half
their army) while Pakistan can deploy 30, assuming none are deployed for counter insurgency.
There are very few Indian formations that have the option of being deployed either against Pak or China. These include part of IX corps in Yol
6th mountain div in Bareilly and perhaps a division from III corps in the North east.
We have 65 tank regiments, of which I would assume upto 9 would be based in eastern Ladakh/ Sikkim. Our 56 regiments deployed against Pak
have 45 tanks each, against the 50 Pak regiments with 42 tanks each. That gives us a small numerical superiority, which would not be enough
for a decisive breakthrough in any sector in the West (especially keeping in mind the need for reserves against the Chinese). The PLA in theory has numerical superiority in tanks but very limited scope for deployment due to the terrain - which favors the defender. At best they can hope to wear out our armour in a long war of attrition - that is the opposite of the battle Pak needs to fight, which is short war, where they can claim they won because they did not visibly lose and before their economy collapses.
Since our doctrine is not to claim enemy territory in a war (where we occupy territory like in POK/ Aksai Chin, the terrain makes it extremely difficult), our existing strength and deployment is adequate to defend our country in a 2 front war (while inflicting heavier casualties on the enemy). We win by not losing (which would also be Pakistan's objective in a war against India without Chinese support).