I doubt many JWs, if they've even cracked open the Proclaimers book once , realize that CT Russell was nothing more than a re-warmed, re-labelled Adventist when he began publishing Watchtower. And, according to Proclaimers, CT Russell did what every other religion/sect/cult does to arrive at its own particular brand of theology: he looked around at that the various religions, adopted what doctrines appealed to him, and rejected what didn't. He took the "buffet approach" to his belief system- simply pick and choose what looked good and pass over the rest.
And, while condemning other religions for having some things right (according to his view) but many things wrong, CTR ended up being in the very same boat; but of course, as the 'faithful slave', he was too close to his own trees to see the forest.
There is little that's unique to WT other than what usually differentiates one wacky cult from another.