Miami isn't even recruiting Devine. He's a way from qualifying at a school like FSU or UF, so he's even a longer shot at qualifying at Miami, who uses substantially tougher standards. FSU is recruiting him pretty hard, but they're short on scholarships so they may have to give the RB scholarship to a RB that would commit sooner. UF is recruiting him too, but not as hard, plus UF doesn't take nearly as much chances as FSU does with borderline kids. I'd say he's pretty open, I think there's a good chance he'll go out of state.
As for Brown, if you just go by his videos, they aren't any more impressive than Davis'. The problem with Davis is that he doesn't always play hard. If you watch his highlights, you can see that he's almost never the first guy off the line. That shows a lack of concentration, which he admits to. But you can definitely see his athletic abilities, as in the SunshinePreps clip, where he chased down a RB and other mobile QBs. The only QB he had problem catching was Jarred Fayson(#11 QB in the middle of the clip) a 5* recruit from last year. Also keep in mind that both Lakeland and Armwood are Florida powerhouses, so they play against some really good competition(in Davis' clip for example, he went up against Tebow's Nease team and Fayson's Hillsborough team, and probably other powerhouses as well that I didn't recognize)
