Your assumptions about China's willingness to escalate, for one. Your emphasis on manpower, for another. Your argument is like me saying the PLA could have taken Taiwan 50 years ago because it could have sent some multiple of the RoC forces across the Strait in rowboats. There's a reason people mocked that idea as a "million man swim".What about that is wrong exactly?
I also question your reading of the geography. China expelled India from all areas of its boundary claim, unfortunately at the cost of limiting its own patrolling rights. The exception (in China's favour) is Depsang, where China is forcefully preventing India from patrolling.
That's what I mean about dubious assumptions. This entire analysis stands on the very questionable assumption that the PLA is going to be restricted to shoving matches and India can always send more squatters to outshove them. It's very clear to me that should India violate the agreements it signed that China would escalate to armed force, which means the 100x manpower become cluster munition targets. This throwing stones and mêlées silliness ends and things get serious. India struggles against Pakistan; it is not equipped to fight a modern war against an opponent like the PLA, simple as. As delusional as Indian leaders are, they're not delusional enough to forget that.If both want to avoid war and India wants to use patrol and pushing tactics to salami slice, how can PLA respond?
China would prefer not to escalate to armed force, while India cannot afford to escalate to armed force. It appears superficially that both sides don't want war, but serious analysis must go deeper than that and consider the asymmetries of costs. It must also not follow dubious assumptions down a rabbit hole.
China has escalation dominance of the situation. It has every incentive to climb a rung if India tries to press a wholly contingent artificial advantage that's entirely confined to the present rung.
That's what escalation dominance means.China is preventing it from using this by threat of war if India goes down that path.
I'm quoting this sentence from your original post because it demonstrates what I consider an insufficient understanding of deterrence and escalation. If you and I are in a fist fight, my objective is to knock you out or incapacitate you. If things escalate to a gunfight, my objective is no longer to incapacitate you or settle a dispute with you - it's to take your life.Even defeating India thoroughly, there is still nothing to gain for China except the 20% and maybe parts around Tawang. Which India would keep contesting.
If China and India go to war, it's no longer about Aksai Chin or Tawang. "Defeating India thoroughly" means a lot more than settling a border dispute.