There is definatly nothing wrong with sword, it's game itself. People tend to sink in the ground, hitboxes are fucked up when they are jumping etc. Some guys with really wierd movement can make your swings glance at their armors, especially right swing when it connects with the beginning of animations it will most likely bounce of your oponent. Wich is something that wouldn't happen in most of the cases with 2h or polearm. Also ovearheads are pretty easy to miss, it happens to me with about 50% of attempts, and it's common amongs other players that use 1h weapons. You probably need to adjust your game style. If you have any performance issues, no matter if it's connection or shitty PC, things that Digglez is talking about are getting even worse.
To be honest the only problem that I noticed with 1 handed weapons hitboxes is with the stab, it seems to be a bit moved to the right side from actuall model and it tends to glance on the guy standing on your right side, but it is maybe coused with the fact that you actually have to spin a stab so even I think that I'm not doing so I did it
it may be the reason that one can call it complete bullshits