I feel like this has been a common theme for Troy this year. They're just not as good as we expected. Still better than nearly everyone in the MVL (Xenia the only challenger), but not as wide of a gap as we thought.
For example, games against Tipp, Greenville & Sidney were all probably expected to be big Troy wins, but all were competitive games. It's become more than just a one time question, so I think that leans more towards Troy not being as good as we thought.
I don't think Fairborn will be much of a test for Troy, but Fairborn has been up and down this year as well. Even though Butler isn't great, 39-0 is surprising. They also played Tipp/Sidney/Greenville tough as well, even though they lost all of those.