Saidar is a calm river, yes... but only till it is pushed. Fight it, and it suddenly flips into a mire with whirlpools and hidden currents. I suspect something trying to stem the flow of saidar would face that.
point being the way a woman embraces saidar is inherently passive while men must seize saidin in an aggressive manner. Males must fight to maintain the connection whereas females float within the embrace of saidar. The more I think about it the more it makes sense that it would take more raw power to cut a man off from saidin than it would cutting a woman off from saidar.
I would image this would be the case ... would explain why Graendal would be able to cut off and shield Aran'gar. It also seems to be the case from how we see Nynaeve and Moghedien attacking each other with blades of saidar while Rand attacked Aes Sedai holding him with fists of saidin.