Joy is hardly progressive, she's a centrist through and through. She does have left leanings here and there, but she's pretty much a centrist.
As for Sunny, she's conservative for her private life, but a centrist democrat for politics. She's said so as much during a discussion when Meghan first joined. Sunny is against abortion for herself, but agrees with separation of church and state and will fight for it for something else. I think her own personal leanings might make her have things in common with Meghan, plus they are both Christians so that helps too. I don't know how practicing Me