They are quite distinct. They both share a certain modern, dry-spicy base typical of Tauer (think Orange Star, Rose Chypree, certain parts of LADDM). In fact, upon first smelling, I thought Loretta to be unbearably so; but in a later wearing somehow this base seemed toned down.
Apart from that, Loretta is a rich, dirty tuberose. It comes off not as huge bright tuberoses a la Poison or Fracas. More the sweetish indolic tuberose of the recent HdP trio. Miriam instead is an older style aldehydic floral (rosy, jasmine, etc). I would think of these as Chanel no 5 and Fracas if they had been conceived by Tauer. Not that Miriam and Loretta smell like that, but to give an idea about where they stand within their solid footing in Tauer's style.