I agree that it's good Willow - or anyone else - wasn't dubbed.
In the French version, it's ridiculous (I could stop right there, cos the French version is generally ridiculous), because many of the usual "dubbers" didn't want to sing so they used other people, whose voices didn't sound anything like that sometimes !! Such as the woman singing for Tara. OMG ! It's so stupid ! But a few things are fine. Luckily the woman dubbing Buffy is also a singer so it was agreeable.
If you're interested I could post mp3s of the French version songs. Some are sorta good.
I have the French songs. So only the Buffy dubber sang in the French version while the others had other singers singing for them. I have to say, the Tara singing voice as well as Anya were were the worst.