>>56562196It would make sense if a Unova Legends happens around the 1600s since New York City ( or rather, Castelia City ) was founded around 1624 before being handed to the British in 1664. By that point, most buildings still would be transitioning from medieval-tier architecture you'd find in rural Europe at that time to those found in urban centres in Europe. It would also make sense if the overarching plot of the game revolves around you surveying and clearing up land in the surrounding areas and starting settlements which would eventually become the cities/towns of the Unova region.
How we'd incorporate Zekrom/Reshiram into the story is beyond my scope of knowledge, but we can try to frame it as "Native Pokemon legend adopted by Galarian Settlers in the region as a symbol to represent the ideals of the people who moved there and the realism of the conditions they are in"