The title of the mod under development is called "Star Wars: Rise of the Shadows." The mod is somewhat based off a fictional timeline setting in the Star Wars universe between Episode 4: A New Hope and Episode 6: Return of the Jedi, but mainly between Episodes 4 & 5. Basically the characters in the mod are involved in a plot revolving around a recently formed Consortium of Criminal Networks (CCN) between various members of recently allied criminal networks such as the Zann Consortium, the Hutt Cartel, and the Black Sun; all of whom conspire with an emerging regime in Geonosis to liberate the planet from Imperial occupation. The Geonosian regime is led by Prago the Lesser, and his military commander Darth Rex, a dark Jedi. Along the way, Darth Rex shares his leadership with his new found love, Serra Nova, a Jedi knight who survived Order 66 in her padawan days. Meanwhile, the Rebels see this emerging criminal faction as a potential ally in their war against the Galactic Empire.
The "three(crimelord)amigos": Prince Xizor, Jabba the Hutt, and Tyber Zann.
Well, technically there's four crimelords for the Consortium if you count Prago the Lesser, but he's not in this picture.
Why has Jabba joined the Consurtium? Jabba hates Tyber Zann
Good question. Well, I could offer two potential reasons. One was that if you follow the FOC campaign story line (and I'm trying to coincide and assume these events were mostly before the Shadows of the Empire time frame) , after Jabba made concessions with Zann following the Hypori droid factory mission, they were more or less neutral towards eachother since Jabba had basically made concessions to Zann to get his life spared as well as end their feud more or less. Second reason which probably follows the first one, is that Jabba and Zann are crimelords and they typically behave that way. They're greedy and they can probably come to terms in putting aside their past feuds in the common pursuit of greed and finding lucrative ways to expand their power base while finding 'shadowy' ways to weaken other potential foes like the Empire. This basically is part of the background plot of the mod; a few months after the Battle of Yavin all the major crimelords are forming a united Consortium to advance their mutual interests for power and greed of wealth while robbing it away from the Empire. Meanwhile the Rebels, though not fans of the criminal underworld, are likely to see this faction as indirect and mutually beneficial allies that serve a purpose in defeating the Empire.