Had someone else other than Jerry bought the team back in 1989, how many SB's do you think we would have won in the last 29 years?
I say at least 6
Do we assume that whoever bought the team would have hired Jimmy Johnson, drafted Aikman, drafted Smith, etc.?
Since Jones bought the team, only New England (five) has more Super Bowl victories than Dallas' three. Denver also has three, while Green Bay, Pittsburgh and Baltimore have two. Plenty would say most of those have been better coached and have had better players than us at key positions.
This does not excuse the team from being more of a contender when it had Romo at QB, it just shows that it's hard to win Super Bowls no matter who the owner, coach and players are.