I'm in IT and six out of the dozen or so managers I've reported to in my eleven years here have been women. (We're definitely a serious outlier—there was at least one time when my entire five- or six-level management chain was female except for the CEO.)
I haven't seen much direct evidence for the competition-vs.-collaboration model in our organization, but there's one generalization I can make: for whatever reason, on average the women have been far more competent than the men. I've encountered several men up the hierarchy from me who were indifferent, ineffectual or incompetent, but none of the women have been, and the sharpest woman I've worked for could run rings around the sharpest man. I suspect this happens because women have to work twice as hard to be taken seriously in IT. The main difference here seems to be that they can eventually get real career traction.
In all cases, IT was a collaboration/support department, subservient to the "men's" departments like sales
And of course the CEO, president or equivalent was a man
However, I think the fact that the #2 person was a woman in all three cases is a win for women.
I wonder if it was subconsciously set up by the leader that way, maybe they feel less threatened by a woman as #2?.
Being in a department that's not in the line of fire hinders the possibility of advancement in the career ladder significantly, I've noticed.