In GC 6: 105, in the list of the "chosen ones" who will "fight for Armida" (in every sense of the word), two names are worth attention. One is a certain Conano, almost surely an Italianized form of ------ Conan. That's something more than mere coincidence because, as it has already been pointed out, Gerusalemme Conquistata modifies the Liberata so as to make it more "barbarian" in both senses: Normans and even Vikings are added to the Christian troops, including the main hero Richard, and the battles turn into bloodbaths, no longer refined Renaissance duels.
The other interesting guy is Tranquillo / Tranquil, a' dolci studi amico, "fond of sweet studies." His name echoes "Torquato"; in fact, this is a brief role that Tasso carved out for himself, as Alfred Hitchcock always did in his movies. Even more remarkably, Torquato will have Tranquil, i.e. himself, killed by the beautiful she-knight Clorinda. A literary and sweet way to commit suicide, as the poet was often tempted to, and "only my Christian faith prevented me," he confided to a friend.