India is the only country that connects all SAARC countries through its common connecting land mass in the center, without India, SAARC has no meaning.
Bangladesh and Sri Lanka can join ASEAN, Pakistan and Afghanistan can join Russia led Eurasian Union and if China can cut off chicken neck and liberate North East states then, Nepal, Bhutan and 8 sister states led by Assam can join ASEAN as well.
India is the most inefficient and dysfunctional nation, a state sponsor of terrorist activity in the region - all countries should avoid dealing with it and look for alliance and association away from India to limit its influence within their borders.
Trade, security and strategy wise, Bangladesh, Pakistan and SriLanka and China can still form sub regional group and if Nepal wants to join so be it. There is greater potential on that.