Vastor and Rudd were deemed too old for the role, plus their love for ancient magical bloodlines was well known. It made them even more undesirable than they already were, even as simple Professors.
Their ties with many of the families implicated with the scandal made their positions precarious at best.
Manohar was considered a visionary in the healing hearts, a true genius, or, to put it in less kind words, a complete nutjob. He was fickle and unreliable, not to mention his biography was full of social blunders to the point of being universally considered an etiquette book about how not to behave.
He resented the Crown judgment, but only until his first visit to Marth's new office. Just seeing how busy his schedule was and the amount of paperwork being Headmaster involved, Manohar was tempted to taking another "vacation."
The Crown had no time to waste with him, so they literally chained Manohar to the academy, just to stay safe.