Hampden-Sydney is typically a pretty good, playoff level team in D3. It's where Nash Nance transferred to when he left UT. Wabash beat them while he was still there a couple seasons ago, I believe. Wittenberg is the current winningest team in D3. They're down at the moment, but it's usually a toss up between us and them for who will win the conference. They usually fall in that 5-20 rank. DePauw is typically pretty good but have been going through a UT-esque drought. They were ranked 9th in the country when we played them my freshman year. We beat them 47-0 and they've been down ever since. Also, your conference is your conference. We play 10 regular season games, 9 of which are in conference. Our only OOC game was against a traditionally ranked opponent, and then we won 2 playoff games. That's pretty good as far as D3 schedules go.
It wasn't legal then either. Jack Bushofsky was their head coach, he offered all the seniors on our offense a group scholarship.
You can extrapolate this argument to basketball and the results are more pronounced. Oak Hill Academy would do more than beat a D3 team....they'd beat Missouri.* *Oak Hill Academy is used because I didn't feel like looking to see who the best HS team was this year, and because they're usually in that conversation.
Oh, in basketball, Oak Hill would crush a D3 school. I don't think they could beat the vast majority of D1 teams though.