I don't know much about the lay of the land down there but for me antelope hunting is all about opportunity.
Sure you could scout out a stud buck before the opener but there may be little to no opportunity.
As for my experience a few years back the good bucks were with does and the little bucks were loners. So if you see a group there stands a chance of having one stud. If you see a loner likely a small buck. No bachelor groups