Reflected in You question

I think Eva would chew Christian Grey up and spit him out.

Gideon would scare the hell out of Anna, and Christian would have no idea what to do with Eva. In my opinion neither switch would work.

Its hard to say the combination is so distinct
First: Ana would NOT be able to handle Gideon. He is far more complicated than Christian.

Second: Eva will scare the hell outta Christian. She has a history and has her own issue which are darker than his and he is barely able to control his own demons.

Third: Ana and Eva are so different:-
Ana is a shy little girl while Eva is a tigress.
Ana has no interesting plot while Eva has her own story going on.
Ana is the secondary character while both Eva and Gideon are in the center.

Fourth: I don't think if the situation was as stated, that Christian would have fallen in love with Eva. Because He needs a submissive and a VIRGIN (*eye roll*) really he does. He would not have given her a second look because she is confident, independent and not a blush-every-second kind of girl.

The bottom line is they are disaster if switched with their partners.

i don't think so either. i think that one of the great things that works for eva and Cross is that they are both VERY STRONG and quite damaged but they succeed on their own.

with Ana and Grey, Grey is damaged but he's strong - Ana - well, she's just naive and still learning who she is, even before she's been in the world. I don't know that she would have had a successful relationship with Cross, just as i think that Eva would not have been submissive enough for Grey.

I don’t think it will happened, Christian love Ana because her pure, her innocent and sweet. Christina won’t be with Eva, not because she is not as beauty as Ana, Eva seems some kind of sexual addict with a “big” breast. And the most important is Eva is blond.

How about Gideon with Ana? Maybe, I thought about it may happen. Just because Ana is the universe type for all men

Nahhh... Cross loves Eva and Grey too to Ana so its IMPOSSIBLE. I don't even think about this stuff. Partner swap is not a good Idea.

I hate Ana and I think Eva would be great for both men. She'd put Grey in his place, probably tell him to man the hell up and it's not only him who went through shit in his life.

I'm still not sure about Eva and Gideon. I think they're too much alike. But Ana just wouldn't do. She should go get some lessons in confidence and how to not be a push over.

Strong female characters are the best, in my opinion.

Gideon was cool, but there was something about Christian that just...creeped me out, now that I think about it...

no ...it would never work out ! the reason eva and gideon work is because they feel each other's pain. they both have history (bad history ) . whereas ana is been brought up like a princess...it wouldn't make a good story to me...!

Ana is too much of a wet blanket for Gideon. He doesn't need a crybaby.

I really don't think that Eva and Christian would be a good match in any way shape or form. Eva would chew Christian up for real! As for Ana and Gideon I don't think that would be a good idea! Ana is too weak and Gideon needs a female that's going to put him in his place when needed and point out the things that need pointed out about him! I'm just now starting the third book to the Crossfire novels and from where I see it right now Ana and Gideon just really wouldn't be a very good match at all! Neither would Eva and Christian though because Christian loves his control and Eva wouldn't be able to give him the control he needs at all!

No way, no way.

Cross would be too much for the poor bird Ana.
Eva and Christian would also not work, because Eva is too self confident and Christian need a sub that obeys.
Eva was too self confident for Cross in some parts already, so Christian wouldn't 'fall in love' with her like he felt for Ana.

Eva wouldn't tolerate Christian for one moment and Gideon would just chew Ana and spit her out.So.....no the swapping wouldn't work

If Ana was Ace girlfriend then she would just be another bimbo who doesn't see Ace for what he truly is . A doormat basically.

Ana would be too shy for Gideon. She could never be with him, it's just impossible. They don't fit to each other.
Christian prefer shy little girls so Eva is definitely not for him. He wouldn't know what to do with her, I think.

Christian prefers brunettes and submissive so he will just ignore Eva when he sees her. Ana might end up in a psych ward because of Gideon.

Ana will be VERY intimidated with Gideon because he's more dominant (i think) than Christian. Eva will not tolerate Christian's kinky F*ckery at all. She's a tigress.