"The Pacific War was unlike any military conflict before it in terms of its scale, scope, and savagery."
I guess the author of that article knows nothing about the Eastern Front.
The PTO was larger than the Russian front and it's arguable its scope was wider (IE variety of warfare, no submarine or carrier warfare on the Russian front) and it was as savage if not more so and it happened at the same time as the Russian front and the statement you quote does state "before".
Other than that you are 100% correct