It would be.
Frankly, the problem is that no one except Julian is especially fond of his ideas of a "revived" paganism. It's not that there aren't still pagans of some sort or another, but Julian isn't exactly representing anyone's belief system but his own - well, maybe a few other odd ducks, but not enough to encourage people to join the Church of Jupiter or whatever he'd call it.
Yeah thats his biggest flaw, he wasn't willing to jump on the bandwaggon of any of the non-christian religious movements of his era and so his traditional paganism was just continuing long discredited practices and favouritizing a tiny minority. Whats needed is for him to adopt something like Neo-Platoism that could be integrated into the Roman Cult in order to reform it into something more worthwhile and appreciable to your average citizen or Sol Invictus (both of which are fun and AH-y enough to try, Neo-Platoism for being like a Roman version of Budhism and Sol Invictus for being the major "road not taken" by history in terms of european religion). Those are the only ones I could see working since the other major choices Mithraism, Manichism, and what he wanted OTL where impossible for various reasons (only popular with the soldiers, too connected to the Persians and completely out of touch respectively..)