It is really odd to me that Bangladesh even exists as a nation, and that it is an officially Islamic nation. This country was formed as a result of the partition of India, where the British empire left a mess on their way out by subdividing India into what is now Pakistan, India, and Bangladesh. But really these countries should be recombined into India - their status as religious ethnostates is unacceptable in the modern world and given that Islam came to the region through brutal genocidal invasions by Arabs in the Middle East, it seems strange to give those colonizing invaders their own land and ethnostate. Pakistan and Bangladesh have also been messy throughout their existence, and continually on the brink - as current conditions show.
I am not very familiar with the backstory here. Are you saying one person pushed for this? I assumed it was a purposeful strategy of the crown, for a departing colonizer (Britain) to weaken a former vassal state that might otherwise seek revenge for hundreds of years of colonial rule.
He didn't push for this, but he was tasked to see Partition through, and he bungled the job, hence "non- guidance". Maybe no fault of his, but you can get a deeper nuance of the larger issues at play by thinking about how he personally could have otherwise done an okay job. Taking the maxim to not assume malice to its pedantic conclusion. Plus, it's easier to think about a constrained space of individual actions and intentions even if the wider politics are so complex.
At that moment in time, Mountbatten was perhaps the personification of the Crown (and he would have known it)
