So, if you hatch a sea turtle X sea dragon and if you are really lucky, could you hatch a new pet that has two spritely talents (one in slot 5 and one in slot 7)?
I highly doubt that. Sit in the Commons on a crowded realm for a few minutes, and observe all the players that have good pets. In other words, check out their stats. How many of the pets in question have two talents that are the same? None.
Either way, how exactly would that work? Would it cast Sprite twice as often? That would be interesting in PvP, but then there would be even more complaints on the message boards about Spritely being overpowered. Then the complainers would be right for once.
Kingsisle would not appreciate this, so it's likely that they programmed the game so that that couldn't happen.