Thanks Bootie & NG, I wasn't aware of that unwritten rule. I understand why one would do it that way.
I also see that playing both at the same time allows for intelligence (specifically, OB & Rein & Terrain) about the scenario, that one wouldn't have, were you to play them subsequently. Seems like having that knowledge would have as much of an effect on the scenario balance, as playing them sequentially. It would therefore seem logical for two players to agree to which way they want to handle this aspect, as opposed to an unwritten rule.
I for one, love the mystery that comes with playing without knowing my opponents OB, rein schedule & disposition. If that means I get the short end once in awhile, so be it. Im here for the long haul and those things will equal out. Besides, Im here more for the camaraderie than the tally.