If you can do that, Wildcard, then props to you but in my experience, no matter how clever your tactics sooner or later you get yourself in a pickle and have to roll the dice and hope! The mino-bus incident I just described was a good example of why you need the stubborn crown just for when the dice go south on you.
I was playing beastmen, running a deathstar with 3 characters and 9 bulls. I tied up his minotaur deathstar with chaff, pushing my ogrebus through his lines to get to the bunker with all the wizards near the herdstone. His minobus turned around. I knew I had the charge on his bunker unit, and it would allow me to push off the board with an over-run, away from the minobus. I hit the bunker unit and massacred the unit down to only two members remaining. Absolute carnage and I was feeling pretty good. But of course, those last two gors roll snake eyes on their break test as my eyes widen in panic* - not only can I not avoid the minotaur charge (and these guys were high on blood and rocking something like +4 attacks each) into the rear of my unit, but my characters are all stuck next to these two chumps and unable to make way! The minos charged in and ... well, it wasn't pretty. 7 dead ogres, including my champion. Stubborn Crown to the rescue, my characters held, next turn reformed and murdered the minos, including critically their Stubborn Crown guy, breaking the minos and running them down.
I've even been contemplating a double-death star build. One deathstar with three characters based in a unit of bulls (possibly a horde) with the Stubborn Crown, a second deathstar build around maneaters with stubborn. It's a stubborn party!
*One other thing that made this noteworthy was my opponent was cool as a cucumber. He throws snake eyes with no re-roll like it's nothing, no shouts or whoops or even a raised eyebrow. I'm standing there stuttering and he carries on like he expected nothing less ...