that blade looks really awkward. The curve should be the other way because the flat edge is a poor shape for cutting and will be heavier than the curved edge. The heavier part of the blade should be behind the cutting edge to create a more forceful cut. That just looks really awkward to hold and use.
Well there are quit a few styles and and the cutting arc is up to what you are using it for and how plus it is not a heavy weapon for those who know of it and its history. The force of the blade is draw from your body. Ask Rome... LMAO