Swordsman might only have 'slightly' better resists, but at the higher levels even the slightest increase makes an enormous difference. the difference between 85% and 90% resist is the same as adding a whopping +50% hp, and the difference from 75% resists and 90% is adding 250% hp. So as it sits now, it seems Swordsman are better tanks(able to reach 90% against all weapon types), whereas knights do better damage due to magic attack.
My concern is less to do with overpowered/underpowered units, and more to do with the overlapping of roles making a unit obsolete. I don't see many cases where the Knight would be preferable to the Swordsman. In a one-on-one matchup there may be cases where the knight is superior, but the lack of blunt/piercing resistances makes them far less survivable in battle of any size, and this lack of survivabilty negates their stronger damage, as they die before they can bring much of it to bear, and the swordsmen keeps hacking away. =/