The thing about both is they are not really leading lady quality. I think Ridley is a serviceable enough to be a supporting actress, she falls into the level of Ben Affleck to me, consistently fine but nothing spectacular. Emma I've just never found all that good outside of Potter. I think she had the real life personality that fit Hermione well, but something like BaTB I'm struggling to see how or why she was cast, especially because it was clear from the first note of the first song she couldn't actually sing.