If India and China could settle the border issue, there is basically nothing to worry about each other, both countries can deescalate and move their military to other places that needed them the most. Both countries strengths and weaknesses are complimentary at each other, they can help each other. Like I said, so much to achieve together. India need investment, a lot of it, and China can provide it. While China can have access to the growing market of India. Both China and India could also represent the global south to block the US hegemony.

I also said before that China need to make up its mind about what to do with India soon. If China and India can settle the border, then great, China can fully cooperate with India in economy and other things. But if the Indians still refuse to settle the border issue in the next 5-10 years, then maybe China need to play for the kill. Do every thing China can to sabotage India to prevent India from emerging as a powerful threat to China. China is already in a great power competition with the US, it is can hardly afford of having a hostile power at its back, ready to strike at anytime.

As for Pakistan, as much as I have soft spot for Pakistan, it is always teetering on the edge of becoming a fail state due to religious extremism, corrupt politics, coup prone military, and ethnic separatism. It is hard to work with unstable partner, as we can see on many Chinese falling victims to terrorism attack in Pakistan. China can't abandon Pakistan, but it is also limited on what China do to help Pakistan if Pakistan can't help itself. All those military equipments mean nothing if Pakistan economy can't take off.