this is an all out battle. the jean grey to be used is her power level just before becoming white crown phoenix (like when she could feel xaviers pulse through the scalpel).
Gender: Unspecified Location: Speedblitzing around the universe f
Oh god...this fight again?
Jean wins by shutting off IW's mind. If IW gets lucky and gets to Jean first, she still has to content with Jean's own forcefield. IW's forcefield MAY be more powerful in the end, but while they're strugging, Jean psychically suggests that IW drop her forcefield, then knocks her out.
The only protection Jean has is her forcefield. She gets hit by anything and she's done.
She was created to give high spirits to females. Hence why she is brains over brawn (literally). Her character is designed to show that you can win without being big and strong. Ironically, she also shows that a punch to the face is enough to take her out.
Gender: Unspecified Location: Speedblitzing around the universe f
I think that's just the nature of the writing. Sue doesn't have enhanced stats. Jean has been hit before by pretty powerful people (like Poccy and Hulk). She's generally cited the "unstable molecules" in her X-suit for staying alive. Given that those some unstable molecules were designed by the F4, I'm guessing that's also the reason why Sue has survived powerful hits. So durability is probably even, since they have identical body armor.