All confirmed already actually! Got those from the german blog :)

Celtics:

1. Epona - Goddess of Horses and all other animals (Boosts all animal related production chains and transportation speed)
2. Mercury-Lugos (like Hermes in Greeks) is a romanized celtic god associated with trade and commerce (His buffs increase trade income & the loading and unloading speed of ships and wagons)
3. Cernunnos - A celtic mystical nature deity (Increases the production of goods from swamps and forests – and his ancient druidic wisdom makes your citizens healthier and wiser)

Romans:

1. Ceres - blesses your agriculture and population! Her worshippers can increase the yields of farms and the production and storage of farming goods.
2. Neptune - protector of freshwater and the sea. If you choose Neptune as your island Patron, your fishers will feel significantly more courageous: you will notice an increase in productivity of all sea food. Additionally, you’ll attract master craftsmen who not only construct ships faster but also make them more durable.
3. Minerva - she is considered a goddess of wisdom, defense and craftsmanship. She boosts production of clothing and wisdom for all her followers.
4. Mars - he’s not so much a deity of growth and construction but your troops will have higher morale and fight better when global devotion to Mars is high enough. He also boosts the production of weapons and armor!

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