But this “overall” plan was basically fictional—it was a model, and apparently not an accurate one. Georgia Tech doesn’t have a unified IT setup; it has hundreds of different IT setups, including a different one at most research labs.

Yes… this is actually common. Your typical state school is actually made up of many different colleges working in tandem with each other. The nursing “school” is different than the law “school” at your university. Often even holding completely different names internally.