I mean, she basically took on Thor's persona. That persona that she exuded around people was basically classic Thor, which made Aaron's characterization for the actual Thor more jarring because he seemed to forget what Thor's actual personality was in favor of him acting like he hadn't grown up much from being young Thor.
She had better control of Mjolnir because Mjolnir was mostly controlling itself. Mjolnir had more to do with making Jane Thor then making the original Thor into Thor.
Well, Eric was pretending to be the original Thor if I remember correctly.
I think the problem was the lead-up to the guy actually thinking he's not Thor anymore and then treating it like a mantle instead of his actual name.