All countries have divergent interests, but geopolitics like politics is the art of the possible, to make the impossible into a reality. And regional integration is always a long term process, EU came this far after 5-6 decades of work.
Of course more internal reform, cohesion and growth is positive, but even to achieve those, I believe you need external help to reduce harmful influences and increase positive influences.
Russia is a wild card in my opinion, Putin and other CIS leaders are mostly former apparatchiks, so this trend to recreate Soviet Union may not last. Of course it will be great if it happens. But I have a feeling that eventually ethnic Russians may prefer to integrate with EU, because of ethnic/racial solidarity.
Enemy of an enemy is a friend, so China will always find some good feelings with Pakistan and Bangladesh, but I am not sure about long term intention of Chinese about Pakistan or Bangladesh. China has border with Pakistan, so there might be more opportunity to work together. For Bangladesh, China is a balancer against Indian influence. But I would prefer ASEAN+ grouping for the balancing of India, because someday it is possible that we can be a part of ASEAN+ grouping as a bona fide member, but there is very little chance that we can ever be an integral part of the Chinese Union (PRC+Taiwan). And we do not have a common border with China.
We are going off topic, so I will stop here.