Okay, I'm not so good at game balance, so balance-wise this might be a problem. What I'm trying to do is create powers that replicate what we see it the books--and from what we see in the books, in a straight fight where you have prepared wizards and don't have enemies with magic resistance, wizards do indeed outclass their mundane allies, unless those mundane allies are people like Marcone or Kincaid (or Murphy, or...). And when it comes to computer hacking, the wizard is outclassed by their mundane allies. Like I said, I don't understand game balance all that well (it's why I keep posting things looking for help with mechanics) but I thought that you were supposed to have different characters be good at different things. (I mean, obviously, if one player wants to have their character be a vanilla mortal who's super good with a sword or whatever, then probably this power shouldn't be used. But can't you discuss that during character creation, or something?)
What it comes down to is, in most games, there's gonna be more combat than computer hacking, and there's a difference between Wizards having a distinct power advantage (which is reflected in the lore and the mechanics), and other characters being unable to contribute in a frequently-recurring aspect of the game.
Say you have a wizard that went all in on this power, and can freely pop off Weapon:3 attacks at a 10. Even if the average goon has a dodge roll of 5, that means the wizard has as good as an auto-hit attack that stands a good chance of one-shotting whatever he hits unless the GM gives it consequences.
Let's say his teammates are a super strong valkyrie and a mortal cop; the Valkyrie, with a sword, can do Weapon: 5 damage on a hit, but her attack roll tops out at 5. Same with the cop -- she's got an assault rifle at Weapon:3, and a Guns score at 5.
Already, the goons that the wizard is one-shotting are dodging half of the rest of the attacks, and taking less stress each time they do take a hit.
So does the GM adjust things to make it harder for the wizard to hit? If so, his allies are now hopelessly unable to hit the same enemies. Does he handicap the wizard specifically? Then the wizard's player is going to be annoyed.
And there's some slippery slope potential here:
There's already lots of "With X weapon, I do two extra stress" stunts that some on this board advocate; so at one more refresh, it's a Weapon:5 sword being swung from a 10, freely each round.
Plus, sword fighting is as much defense as offense, so why not argue that you can use that super-high bonus to deflect attacks just as easily, with no stress cost?
Actually, you've explained my objection perfectly: the knife/sword/fist is superfluous--so why should it be there? If you want an earth evocation, do an earth evocation. If you want to make an attack with a sword, then you get the weapon rating of the sword. If you want to use earth magic to make a really effective attack with a sword, then you should still get the weapon rating of the sword--or the sword should not be involved.
You're getting too hung up on the flavor. Dresden RPG is not a simulation -- ultimately, stress
does not represent how much literal damage has been done; it is an abstract that represents how effective the attack is at taking someone out. That's probably part of why the attack roll adds to the damage — in theory, a single stab with a palm dagger is as effective at killing someone as a supernaturally hot plasma blast from Harry's rod.
Why have one Warden throw fire as a green ball that bounces across the ground, while another shoots little stars? Why have Ramirez specialize in Water evocations when, mechanically, it does the exact same thing as Harry's fire evocations? Why have Billy turn into a werewolf when holding a sword will do about the same damage without worrying about shedding all over the couch?