Having Simmons defend PF would be a mistake.
Simmons would have a big adv on the offensive end against most sfs and the size/strength/length to cause sfs issues on the defensive end
only when you have a SF/SG or if another team goes small ball , Simmons sb be switched to the PF spot
Amir
KO
Simmons
AB
IT
Mickey
Crowder
Smart
Hunter
Rozier
without considering draft picks, FA and sully, zeller, turner, Jerebko
You think he can't defend the 4 because he'll get over powered? Think about the top PF's in the league: Davis, Love, Griffin, Millsap, Bosh. All of the them need to be defended on the perimeter as much as or more than in the post. I think Simmons would hold his own there. Much better than trying to guard Lebron, George or Durant on the perimeter.