There have been plenty of threads on this. Let's look at it from the other point of view. In this country, walking up to a random girl is seen as weird BY GIRLS TOO.
After a couple of drinks, not only is a man more confident, but a girl is more likely be open to the approach of a stranger.
In a country, America for example, the guys may be more confident to go up to a random girl, but only because the girls are on the whole more receptive to it, so there is nothing to worry about.
Maybe I'm barking up the wrong tree...