I'll chat it up since nobody else knows much. I don't know any of these teams very well. But I know why you are asking with it being 3 of Gretnas first 4 opponents.
Nottoway is historically a .500 team. They have had a few good years in the past, a few bad. Unfortunately, they open with Greensville County. I don't think you will get a feel for how good/or not good they are from that game unless they drop that one. Should be 1-0 going into your game.
I don't know a thing about Brunswick except for a few years ago they had a phenomenal track and field athlete by the name of DeJuan Seward. Looking them up reminded me of him, I see that he went to Ohio State to run track. Judging from their record last year, it should be a fun game to open the season with. Both teams should get a good idea of who they are going to be based on whether or not they win that game. Not that losing it means the end of the world.
Radford will potentially be going into that game winless. At best I see them being 1-2 with a brutal schedule. Your best bet to get a read on them would be the benefit game against Auburn or the Fort Chiswell game the week before. Radford going up to 2A should be interesting. I don't expect them to fall off much but they could be sneaky good with a bad record going into that game because that schedule is brutal.
Probably didnt say anything you didn't know, and definitely nothing that you couldn't look up. Good luck this year to your hawks.