Stag's Fury

The question is.....how many people were defending Storm's End? I always reckon that Stannis only left a token force in Storm's End and took everyone to Blackwater, and then retreated to Dragonstone, headed to the Wall and never gave much thought to Storm's End. Although then again, Mace Tyrell still couldn't take Storm's End that whole time prior to heading back to KL, so I guess it was pretty well defended?