My biggest worry for this series is the lack of rogues that might be available. I would imagine all the Gotham rogues are out at least for another year or two and that show has burned through a good number of them. Batwoman just doesnt have that core baddie to balance her out unless you count her sister. Of course the DC universe has many hundreds of evil doers she could fight. Time for the Black Spider to make an appearance
Well, the Arrowverse shows have mixed and matched villains before. Look at all the Batman villains Team Arrow has faced. And Supergirl has drawn heavily on the Superman and Legion of Super Heroes mythoi for villains and supporting characters.
Hey, if the show is set on Earth-38, maybe Batwoman could face some doppelgangers of now-dead Arrow foes.