One is the quintessential story teller and serials writer, with long stories there mostly for the purpose of entertainment : Dumas.

Whereas Hugo was an art theoretician, fighting the "Bataille d'Hernani" not only writing novels but poetry, verses, theater, and he was also very political, going into exile after Napoleon le Petit's coup d'état. Les Misérables isn't exactly politically neutral, unlike the Three musketeers...

There's a reason Hugo went to the Pantheon as soon as he died whereas Dumas was only transferred there quite recently...

Un roi sans divertissement est un homme plein de misères