Hutt would be a great start but a lot of people would love to see Hondo Ohnaka and Prince Xizor as well as commanders. Sculpts could include a variety of aliens from the Cantina or Jabba's palace. Skiff as heavy, or rancor. Bodyguards, extra operatives to fit in multiple bounty hunters over special forces (which they would lack)

I still think the compromise would be a general faction with subfractions being handled through keywords lending synergy for specific units and characters accompanied by a good stock of non specific units. This way you could for example play an alliance of Crimson Dawn and the Hut cartel by running Drydan Vos and Bib Fortuna alongside units for their factions or go full Dawn with Drydan and Maul. Fielding Xyzor with Pyke units would still be possible but work poorly.

I wouldn't mind them as Personnel upgrades or maybe Operatives but not as a faction.