Well it's a tough thing for me to say. Initially I think no, but I also think initially we had more of a 'tribal' lifestyle where things like raising children was a group effort and the weight wasn't placed on just two people. That to me does not mean that there wasn't that 'extra special' connection between just two, but it may have been not as large of an aspect.
Today it's an odd topic, firstly the only times I've seen polyandry come up on major media is when referencing a Fundamentalist Mormon woman who wanted to escape with her kids. It made it seem horrific, they made it a very victim heavy situation with that case. Then you see it in pornography and it's a very sexual thing, which many may see as immoral.
So the current general public's views on it has reasons for it to be given a negative glance. I think that keeps people from taking a step back from everything and calculating on a completely neutral base.
Then again maybe my opinion has distorted my view, the fiance and I have discussed many times if we ever met a girl we both loved and wanted, and she felt the same for us we would have a 'group marriage'. I have a friend who's in the same type of relationship, two bi-women and a straight man, they're raising two children together and are some of the happiest people I know.
Sum it up with I think it was possible to be natural, but so natural it wasn't looked at as odd. I think the way modern day portrays it makes it seem very unnatural.