You can think of this game as having 4 "levels": High D1, low D1, D2 & D3. Below a "B" prestige in D1, you will still need to pulldown some recruits (lower than that and you will often get a flat "no"). However, since prestige (and even conference prestige) impact the value of effort at D1, far more than D2 & D3, you really have to anticipate that some A prestige school is going to jump in on the day of signings.
Baseline prestige is only really useful to think about for the effects of bonus cash and conference prestige. Here's
the link from above. It boils down to the Big 6 and Mountain West (due to geographic isolation and baseline prestige of many schools) being the ideal spots. There is a second tier of A10, CUSA, Horizon & WCC that can be strong conferences, but usually aren't top to bottom. Due to the budget impacts of bonus cash, it is tough to stay at any other conference and be able to battle successfully.
The perverse effect of EE's on everyone else (as much as the A+ schools *****) is that, say, a Syracuse or UCLA often has 6 open scholarships, and A+ prestige and a boatload of bonus cash and carryover. Unless you notice they are battling another A+ whale, then they just win and you get to pick up the scraps. The reason there are so many late "poaches" is the practical matter of having to show that you have enough cash to sign a recruit to prevent getting into a battle or being poached yourself. When I first got to Penn State, I flushed ~$180k down the toilet losing battles to Syracuse in my first 2 seasons...2 battles. One was stupid and the other, well, I thought Syracuse was in a battle with Maryland or BC or UConn and I would have a chance...not so much. This is the same skill you develop at D2, but there never is that tremendous dropdown that you are waiting for.
I think the thing to look for is a team operating well below their baseline. So, if your were eligible for Gonzaga, Marquette, UNLV, Xavier or some Big 6 team that has been horrible for a few seasons, then I'd take it. Granted, the hardest thing to do in this game is to rebuild a bad Big 6 team. So, the non-big 6 decent baseline teams in a conference with a few others, might be the best way to go. At least you have some hope of building it up into something.