I think they are ranked as high as they are because divisions are basically split in half now. So teams like Northeastern and Shelby (I know nothing about either team, other than they are currently #1 and #2 in 3A), may be ranked higher than Reidsville overall, but because everything is split up (or watered down, however you look at it) teams will seem to be ranked a little higher than normal. So instead of being #2, Reidsville would essentially be #4 in the old, traditional division of 2A.
Prime example would be West Craven is currently #4 in 4A but was blown out by Northeastern last year in the playoffs. Maiden is also #3 in 4A and they lost 28-0 to Shelby last year in the playoffs. I know that was last years teams and have no idea who those teams bring back, but not sure Reidsville should be below either one of them right now.