Ok, I've been through the instance quest, "Showdown!", in the Old Jailhouse, where all the Wild Bunch members are, including Old Man Bronco, & I think this instance quest may need some extending & improving.
That said, here are my thoughts...
When Wild Bill Peacock said, "Jane, Bat - you come with me. Billy, Big Bill, - you head right. Pirate, you and Duck head for that tower. We'll meet you in the middle.", but we don't head into that abandoned tower, only into the field where the Wild Bunch mob enemies are. I'm thinking that tower should be the setup for an ambush with Waco Kid as the rematch battle with Waco as it's first battle. & after that, there should be rematch battles against Ike Bronco & Buck Bronco before the showdown with Old Man Bronco.
Here are some thoughts about adding at least one new boss cheat to Waco Kid, Ike Bronco & Buck Bronco. Here's their cheats.
Waco Kid Cheat) - At -50% of his health, Waco uses a new power that shoots a circle of electric sparks towards his targets in 4 fixed directions at once while spinning around fast, gives -25% Accuracy & Dodge debuff. Occurs every 3 rounds until defeated. Speech - "This Kid ain't willin' to go quiet with you so-called heroes! I'll show you why it is so!"
Ike Bronco Cheat) - Every 4 rounds, Ike unleashes a cone attack of electricity to damage his targets, familiar to Bonnie Anne's power, reduces movement by -2 squares & gives 25% Accuracy debuff. Speech - "I told you that you're gonna pay for takin' me to the pokey! Like I said, we're the law!"
Buck Bronco Cheat) - At about -75% remaining of his health, Buck begins to use his Shadow Step power, only to leave a trail of fire at his path that lasts for 2 rounds, & continues for about 4 rounds until defeated. At -25% remaining, the duration shortens to 3 rounds. Speech - "You thought catchin' me was that easy before? Think again!"
And here's some thoughts on improving the last battle with Old Man Bronco, & it should include the last rematch against Waco, Ike & Buck, listed as new "King" units with him, & adding two new cheats to go with his cheat of bringing in more enemies.
Cheat 1) - Every 5 rounds, Old Man Bronco uses his modified shooters to do a flamethrower-like attack at a fixed direction to his targets, DOT lasts for 3 rounds. Speech - "Our way of enforcin' the law knows no bounds, "lawmakers", & it burns, like our hate for you all!"
Cheat 2) - Speech - "This place is where my boys ended up, thanks to Wyatt. Now, it will be your own hoosegow! Boys, surround 'em!" (improvement via speech)
Cheat 3) - At -45% health, Old Man Bronco throws bombs at his targets at a random location, only they spread fire through 2 fixed directions, fires last for 3 rounds. Occurs every 4 rounds. Speech - "Y'all think the law's all fair & square to ya! Well, not the way we do it 'round here in Tumbleweed!"