shouldn't twist of the tongue be a lvl 25 PeCo spell?

Hi,

The guideline used by the spell is 15 = cripple a limb.

The spell uses then voice, and then add a target part.

I really don't get why the spell use a target part since the guideline, itself, already encompasses that.
The result is that the spell is the same level as a spell such as incantation of the milky eyes, which is based on a higher base, and that both wounds are not treated as the same level: milky eyes is healed as a heavy wound by magic, and twist as a medium wound.

Besides, both prevent someone to use the thing affected : milky eyes make someone unable to use a sense, which explains his level 20 and heal as a heavy, which is the same as the level 15 "normal" guideline. (one magnitude higher because of unability to use) for twist, it goes 2 levels higher and doesn't as much, follows the previous logic.

What do you think?

Milky eyes uses a different guideline, destroy a sense which heals as a heavy wound. The same would apply if you destroyed the sense of touch. Crippling a limb will always be part however in order to target a specific limb.

Then why don't the guideline say : "part target should be used" as some other guidelines say "effect is ritual" or "cannot have duration higher than momentary"?

It's not really an answer since I'm already convinced the guidelines were not balanced at game launch, but well I'd hoped for an explanation why such a spell would have an extra 5 levels, making it effectively inefficient.