-Aroma Lady Thyme with Goodra (Mauville Food Court)
-Lorekeeper Zinnia, First Battle with Salamance (Granite Cave)
-Lorekeeper Zinnia, Second Battle with Goodra and Salamance (Sky Pillar)
-Dragon Tamer Nicolas(I think that's his name), Second Battle with Salamence (Meteor Falls)
That's it for all trainers in ORAS.
Source: At the end of this page there is a list of Trainer Classes in ORAS, I flipped through all of them and spotted the pseudo-legends.