While (internet) sources all agree on Aldebaran and Antares (Aldebaran/Tascheter as The Watcher in the East and Antares/Satevis as The Watcher in the West, there is no apparent consensus on Regulus and Fomalhaut.
For example, this source, probably quoting Vivian Robson, names Regulus The Watcher in the North,
(...)In Persian it was Miyan, ‘the Centre‘ and Venant, one of the four ‘royal stars’ of the Persian monarchy, where in 3,000 BC, as theWatcher of the North, it marked the summer solstice.
...while this one (quoting p. 255, "Star Names", Richard Hinckley Allen, 1889 who, in turn, quotes Dupuis) places Regulus in the South.
So, too, it was the leader of the Four Royal Stars of the ancient Persian monarchy, the Four Guardians of Heaven. Dupuis, referring to this Persian character, said that the four stars marked the cardinal points, assigning Hastorang, as he termed it, to the North; Venant to the South; Tascheter to the East; and Satevis to the West: but did not identify these titles with the individual stars. Flammarion does so, however, with Fomalhaut, Regulus, and Aldebaran for the first three respectively, so that we may consider Satevis as Antares. This same scheme appeared in India, although the authorities are not agreed as to these assignments and identifications; but, as the right ascensions are about six hours apart, they everywhere probably were used to mark the early equinoctial and solstitial colures, four great circles in the sky, or generally the four quarters of the heavens. At the time that these probably were first thought of, Regulus lay very near to the summer solstice, and so indicated the solstitial colure.
Because Leo / Regulus marks the summer solstice, I've also fired up my trusty Stellarium, with inconclusive results: on June 21st 2019, at sunrise and 8:54 (time of solstice), Regulus is in the NE, while at 10:45 it is in the E (rising).
So, my question for all you astral mages out there: North or South?