I have two problems with your assessment. The title indicates you believe going 5-1 in your division should mean you win the division. There is no truth to that what so ever.
The second aspect is your comment "Bad luck Cowboys."
Proper preparation prevents piss poor performance.
This has nothing to do with luck. This is a GM that should go back to oil exploration and a head coach that should get fired and start as a position coach and learn the game from the ground up. And a bunch of players that are over-valued by both of the above people.
Luck has zip to do with this.