Luck favors the prepared. Didn't Jimmy Johnson say that?
The 90s Cowboys were lucky too. If the Packers hadn't won a meaningless game against Phoenix, they would have had the first pick in the draft and would have chosen James Francis later in the draft but Seau was better). If we had done that, we likely don't get Emmitt Smith.
If we found a team to trade up for prior to Cincinnati, we don't get Emmitt Smith because we were trying to get back up in the draft to take Francis. Furthermore, if we don't jump up to Pittsburgh's No. 17 spot, Atlanta drafts Emmitt Smith instead of Steve Broussard.
Luck is a part of the process. But you still have to have a process. The Cowboys could have panicked and picked a defensive player or even an offensive player. But since the players they wanted weren't there, they picked the best offensive linemen available. And, as they say, the rest is history.