This time of year is breeding season, so all the males are going to be 'protecting' their territory and women folk. I don't find Embdens to be any more or less 'mean', since my Pilgrims and Roman Tufted are also argumentative right now.
I find the females have the dark feathers on their back, where as both males and females may have the dark/gray feathers on the head. You're mostly looking along the back.
[edit] I should be getting pips tomorrow on my 3rd hatch. The waterfowl are really keeping up with the laying, so I'm going to keep hatching ducks as long as I have eggs. I think I have enough geese set now, though. As long as the hatches work out.