India being surrounded on all fronts by effective fighting forces(strong China, strong Pak, and strong Bangladesh) would be a strategic nightmare for India...worse than the eastern and western front faced by Germany in WWII. It would split their numbers of troops, assets, and logistics. There wouldn't even be a need to fight...just the thought of 3 potential fronts would keep India at bay...they would be ready to negotiate peacefully rather than opting for war. If still they opted for war, that would be the end of India.
BD just needs to build up militarily and have a loose military alliance with China/Pak...like holding military exercises, some commonality in training, and ideally some degree of interoperability of military assets. This would ensure BD remains free to chart its own path and India can't dictate BD like it does for other satellite states(Nepal, Bhutan, Maldives).
Bangladeshi ppl need to realize that India has the goal to be a regional power...at the very least. Sooner or later there will come a time where BD would find itself at odds with India...at that moment BD would have to either get in line like a satellite state...if it's not strong enough...or be strong enough to have its own voice heard.