I've seen
issues like this one coming from a long way off.
I tried raising objections to having to spend a Talent point onto Backstab, and also suggested it become part of the weapon itself, but that got nowhere. In fairness, though:
In an attempt to offset this, one might consider picking the Backstab talent (only works with Daggers, and all attacks are crits if done from behind). Since crits do 50% more damage, and we can (theoretically) Backstab for all of our attacks, our damage is now on-par with the Strength weapons.
I didn't do a lot of testing - but with the testing I did do, I realized that the backstab did put the dagger on par with the maximum damage of the sword... but that's the maximum damage - the sword usually does less damage than the maximum.
Essentially Backstabber is giving you consistent damage at the maximum power, instead of the larger variation from the regular sword.
I would recommend 1 of 2 changes. Either increase the base damage of daggers to be equal with Str based 1-hand weapons, or make Backstab a built-in dagger feature that can occur alongside a regular crit strike (This would STILL be weaker than Str weapons as getting a backstab is effort that should reward with higher damage, not just equal).
If daggers were also granted a higher base critical damage bonus that may also help with their identity and balance.
I believe that points into Scoundrel increase critical damage.
It's late and I have more thoughts on this, but they'll have to wait.
