I also think it's clear from the text, as well as from an RJ quote (IIRC), that men are more difficult for women to shield than other women are, so a level 1 woman would theoretically struggle to shield a level 1 man whereas we know a somewhat weaker woman can maintain a shield on a stronger woman (i.e. a Level 8 woman can maintain a shield on a Level 1 woman)
I'm not sure that I agree with this. I think that men hold more volume of the Power in general and that is what needs to be overcome. Men are generally stronger, but I think that a level 1 man and woman have equal shielding abilities against one another. You're just more likely to come across a level 1 man than a level 1 woman, so women usually feel that they need to shield men in groups considering men are more likely to be stronger and women can't sense their strength.
At high levels I think all the male Forsaken can shield the Forsaken women but the opposite is not true (I mean cut them off from the Source while they are holding the Power). The males hold a lot more volume and can smother the women.
I'd have to go hunt for it though.
Also we say Graendal cut off and shield Aran'gar with no angreal to help her. Which goes toward skill and dexterity playing some role in this dynamic. I don't know that males can "smother" the females as easy as that either. Skilled channelers have been shown to fight off shielding attempts. Graendal rebounded Verin's circle, given there were angreal involved as well as linking that seems to come down to ability not really strength.
Shielding just seems like one of those abilities that some have great skill with and others do not ... Look at Asmodean, he had months to break Lanfears shield and could not do it. Even Moghedien could unknot a shield that was tied off in moments.