Glaive's power levels are all over the place. On one hand he's strong enough to overpower Vision, whom by feats is tougher than WW and possibly stronger, and on the other hand he's getting kicked around by Black Widow.
He has the advantage of his glaive seemingly able to cut through anything, even a vibranium laced Vision. So if WW tries to block that with her bracers or shield there's a good chance it will simply cut through them.
But if Glaive had trouble landing hits on Black Widow then WW should be able to just dance around him and cut him up.