That has nothing to do with dubiousness. The only argument to be made there is a lack of consistent standards. Your point about Hyderabad leaves out one rather

That has nothing to do with dubiousness. The only argument to be made there is a lack of consistent standards. Your point about Hyderabad leaves out one rather important detail: it was an openly-hostile, pro-Pakistani and anti-Indian state smack in the middle of India; that too a large part. From a political and national-security perspective it made absolutely no sense to leave a sovereign, hostil state in the middle of India. Keep in mind the administration was trying to keep the country together and not get it fragmented. It wasn't as if India suddenly annexed Hyderabad. There were negotiations going on as well as well as diplomatic overtures. Towards the end, everything was made quite clear when the Prime Minister of Hyderabad, Laik Ali, stated "India thinks that if Pakistan attacks her, Hyderabad will stab her in the back. I am not so sure we would not." Considering the situation, anything other than annexation would have been foolish and would have put India in a far weaker position and could quite possibly have led to further fragmentation as well.