As a Timberwolves fan, my opinions of Jimmy Butler aren't exactly positive due to how he left here. That admission out of the way, the Sixers would be nuts to sign him to the kind of large, long term deal he wants. Jimmy Buckets will be 30 by the start of next season. In eight NBA seasons he has played more than 70 games on just two occasions, one of which was his second year in the league when he was getting 26 minutes per game and the other in 2016-17. Butler is very good, but you can find another 2/3 swing player a lot more easily than another Ben Simmons. For all of his flaws, finding another Ben Simmons would be much harder than finding another Jimmy Butler. I would take Butler over Simmons any day. Simmons is a 6'11 guard. Height is all he offers. He can't make a jump shot to save his life. If he put on some weight and plays down low I may change my mind but Butler is my choice between those two.
Speaking of Simmons, a straight up deal of Simmons for LeBron won't work due to the salary disparity and luxury tax issues in Philly.