Per First Contact, the official policy of Star Fleet, no matter how life endangering the situation, was to sideline anyone from combat with the Borg who had ever been assimilated by the Borg.We have to give this highly decorated, outstanding officer, who not only became an Admiral after returning to Earth, she did dispatched the Borg but has been the only being in the universe who made deals with them. If a Captain can do the unthinkable with the Borg, just imagine how she could've handled Odo's people?
They took Kathryn's ship and gave her a desk. Her job is to tell Captains of a certain age, who can't work email, what it is they are supposed to do "today" even after there was no more Borg anymore.