Sword and board knights are perfectly workable builds in this game. Probably not too good in pvp, but:
1. Skills are more important than build in pvp. A good build won't help you if you don't pvp routinely, and if you're good at pvp, you'll be able to beat people even if your build is highly suboptimal.
2. Aside from the three invasion-crazy areas (two of which are completely optional for a reason), you can play most of the game without bothering with pvp. I personally don't care about it anymore.