Dyaus Pitar probably became Jupiter among the Roman Gods, and Tiwaz which became the Scandinavian Tyr much later. The latter was identified with Mars by the Romans.
Theria could also means the wild animals. I think she was identified with Artemis, but it probably depended on the place and time. Artemis of Ephesus blessed the crops. Perhaps there was a transition from a hunter-gather lifestyle to a farmer lifestyle, and the deities changed later than the ways of life.
The mythic sequence of Orlanth consists of different periods, including the Lightbringers' Quest, and in the end he was alone in the Underworld, because all the other Lightbringers were lost too. It is something an Orlanthi may heroquest into, but this can be extended to the whole clan in the Sacred Time, possibly emphasizing that particular aspect of the quest.
The wives of the Tarsh Exiles are Maran Gori, but I think it is strange because they do not have fertility. I think some goddess like Mralota or other might be more suitable to the needs of everyday life.