OK, sorry for my misinterpretation.
To your point, how many of that 10K are graduate students?
We'll based on these two links I'd say that 10,000 was the size of the 2013 undergraduate class at Ohio State. Graduate students added in excess to that number.
www.osu.edu/features/2013/spring-commencement-2013.html
www.dispatch.com//content/stories/local/2013/02/20/Obama-to-give-Ohio-State-commencement-speech.html
The reported incoming freshman class at Ohio State was 6,607 in 2009 (6,041 in 2008).
Using ball park numbers, at least 30% of graduates from Ohio State this year did not enroll as freshman at Ohio State. Sure a few may have been accepted originally and transferred in later; some may very well have similar qualifications as the freshman stats they're touting. But I believe you are being disingenuous if you believe the transfers do not negatively, and significantly, affect the freshman metric you've been describing.
Is the dilution of the incoming freshman class to this extreme comparable to any other universities in the state?
Comparing OSU (or even a Michigan or Virginia) to Harvard makes no sense. It's completely invalid. I think looking at OSU in that regard vs. whomever they benchmark themselves against is a much more apt comparison.
The advertisement OSU and Harvard are using for leverage is the same. When Harvard says, "Look at my Freshman class as an indication of the academic strength of our student body", their statement holds weight because their student body is uniform (the Harvard alums you run into on the street in the working world are the alumns who came as freshman to the main campus with a significantly high degree of certainty). Admittedly I don't know what the difference is between Harvard and OSU relative to Freshman through Senior year continuity, but that is my hypothesis.
When Ohio State tries to make the claim, "Look at my Freshman class as an indication of the academic strength of our student body", their statement is invalid in my eyes, because 30% of their product is diluted with an unknown population. Until they release the high school qualifications of these transfers and adjust the incoming freshman class accordingly, Ohio State is being duplicitous.
Are other universities misleading the public with freshman class stats? Sure. But there may not be a bigger offender on the market than Ohio State.
Also, you're fixation on Cincinnati is strange to me. Why do we have a birth right to a more competitive freshman class metric? (Which again, my personal opinion is this metric is not worth fighting for at the non-elite level. We have other talents such as interpersonal skills to highlight).