That's an interesting idea !
You know, i myself always try to re-imagine the dol'guldur fight scene, wich will properly respect the lore, i was hoping to see the three rings more involved since we were promised that this particular scene was extremely beautifull, but unfortunetly it didnt add much material, i mean we didnt even see the strongest of the three, vilya ! I always try to think of Saruman the white using his light powers, since in the book it was by his devices that sauron was driven out of Dol'guldur, it wasnt explained if there was a fight or not, but logically why Sauron would place himself near the presence of the white council, unless he is very prepared for them, i actually think Sauron may intially had taken dol'guldur to draw the white council to him, and slaughter them. Also Galadriel in her dark form was cool, but not very lore accurate, i dont mean i didnt like her, but we know galadriel can take the dark side only if the ring was given to her, and she accepts it, but anyway i could think she was a powerful witch, and she could a lot of magic. The thing that pains me most, is we didnt see much of the lady of light, i mean she is called the white lady, lady of light... These names bind her to the light and good in the world, i actually think the battle should have gone this way ( note that i won't say galadriel will heal gandalf, since in the book he already was strong and helped them fight against the Necromencer):
The white council arrives, they find sauron waiting with his nazgul, and maybe orcs, or guldur' guards ( i imagine them exactly as they look in ET ), they all fight, and sauron lets his servants divide the white council's forces, he heads for galadriel, but her friends know she is strong, but even stronger as a healer, saruman or elrond would stand and defend her from sauron. Sauron does some foul magic that weakens them all, Galadriel tries to heal them, but she is weakened too and forced to use nenya, sauron then knows she got the ring of adamant, he uses his control over the rings of power, only to be stopped by the wielders of Vilya and Narya, he then says a fancy line : "i am the lord of the rings, and what is mine i shall have !", he then uses their rings against them, they are all weak and fall into the ground. Sauron comes near to galadriel trying to behead her, saruman then comes and show his power of the istari, and his blessing of the valar, sending all the nazgul into hiding , and making Sauron crawl back into the darkness, Elrond asks what happens, Galadriel says: it is Saruman unleashed ( like the Isengard unleashed thing from Lotr TT), the ring bearers stand and with THE HELP ( DEVICE ) of Saruman they banish Sauron. THE END !
HAHA this is just but a tought, i think of many possible scenarios, i just got this one in my head right now
PS: this is an interesting thread, do you think we should create another appropriate post for it ?