So much of the balancing issues in this game come from the nature of the damage system, that is, it's exponential. Speed * PS * Damage. If you increase just one value, it's an incremental improvement but if you improve two values, the difference is huge. Coupled with pierce damage for pretty much every stab in the game, there is hardly any damage mitigation. Since stabs are straight forward, and daggers have such a short range forcing you to move forward the whole time, you will always have a full speed bonus, unless your opponent is back pedaling.
The damage system for stabs specifically should be reworked if you ask me, since in my opinion they are one of the most problematic mechanics of the game.