The Kings are going nowhere as it is. Neither Fox nor Haliburton are franchise guys and the Kings haven't made the playoffs in 15 seasons. I would certainly take a chance at trading Haliburton for Simmons to play alongside Fox. Simmons won't have to be the primary ball-handler on offense, which might be a good thing for him. Worst comes to worst, the Kings can help Simmons rehabilitate his image for one season and then trade him next offseason for a massive haul of picks/young players to jump-start their next rebuild.
It would be the best thing in the world for him, imo. It would force him to actually grow his game and do things that he's not comfortable doing.