Interesting topic here, because I've always felt as some have stated that women have a tendency to work better with single arm.
I would add the following comments:
I think the double arm technique, is a very U.S. dominant technique, while single is very European, especially Eastern European. Historically, Willie Banks, Charlie Simpkins, Mike Conley, Kenny Harrison, and now Walter Davis have been the big U.S. jumpers and are double armers, so I think that has led to and continues to lead to people in the U.S. double arming it. Sorry, but the U.S. women are all but non-existence, so no role models there.
Markov, Lebedeva, and the rest of the whole Eastern bloc, which has had huge success in the triple jump, have been primarily single armers and I think sets the role for those countries to follow. (I think Markov was single off the board, not sure rest of phases)
Single arm in my opinion and the low trajectory and speed people see, is closely related to it being much more of a running action than that of a double arm which becomes much more bounding like.
Strength in my opinion is irrelevant to the issue, because I have a feeling that Lebedeva could squat well over three times her body weight.Markov too, although he comes from an era where the special vitamins were much easier to slip through the testing system.
I have found switches hard to make, because of the time it takes and as Lorien points out, what's natural is hard to undo.