You said his growl was weaker. What he's doing is not a growl, it's a scream. Different technique, meaning you can't really compare them in terms of strength. Deep growls just always sound more powerful than screams.Yes, it is a different vocal style on that album than he previously used, but I don't recall ever saying that it wasn't and don't see how that changes anything that I said.
Except Jari from Wintersun, who has a really fullthroated scream.