I mean ideally we're all rooting for Danny to return to form AND for Simmons to turn out to be a starting caliber player.
But if DG is going to shoot 30% from three and get torched by Lou Williams on D for the rest of the season, you pretty much have to make a change soon. Either Simmons needs to get up to speed which will probably take all season or you have to figure out whether Anderson can hit a corner three and defend the starting guards of the league.
I'm actually of a mind that Simmons makes more sense with the starters than KA so long as Kawhi is shooting >40% from three. Neither is a great shooter, but having someone who can get to the rim at will opens things up for Kawhi and Lamarcus on the outside and vice versa. Part of our problem right now is that when we get into our 2nd and 3rd actions, we're asking Danny Green to initiate something from the wing. Having a guy that can slice through the lane while the defense is still moving side to side will draw a ton of fouls and get a ton of good looks for whoever is under the basket.