So far, many people in the Wiki's community have written pages on legendary items within the Pre-Sequel. That said, there are still more to go.
In Borderlands 2, every manufacturer made a single legendary variant for each weapon type (Bandit made one rocket launcher, one assault rifle, one handgun, one shotgun, one submachine gun, et cetera). The only acceptions to the rule were Maliwan, who manufactured both the Pyrophobia and the Norfleet, and Hyperion, who manufactured both the Invader, and the Longbow. However, the Norfleet and the Longbow were not only both E-Tech, but both were treated as uniques as well.
If this remains true to the Pre-Sequel, then know EXACTLY which weapons we are looking for.