I'll give my two cents with the caveat that I am far from an expert at approach. From my experience having a girl wingman can be very effective, especially if she is attractive.
I went out to a few international happy hours with my old college drinking buddy and his cute Russian wife last year. They like to live vicariously through me and hear about my dating stories and were encouraging me to make some moves. I wasn't really feeling it, but I said "Fine, go start talking to the most attractive girl in this bar and I'll come join you and then you can dissapear after a minute, we'll see how it goes."
It worked phenomenally, and I was chatting with cute girls and making friends all night. I didnt attempt or make any pulls but that was more a matter of limited sample size and the fact that I ended up hanging out with a few girls who had boyfriends with them at the event.
Girl striking up a conversation with a girl is way easier and less threatening than guy approaching girl and gives you a very easy in. If she is attractive and cool it also gives you an element of social proof and preselection, both of which are very powerful.
Now, if you are a master A+ level seduction artist I suspect its more dominant and attractive to swoop in like James Bond than to rely on another girl. But if you are like me and hate / suck at cold approach I'd highly recommend giving the girl wingman a try if you have the opportunity.
