I'd prefer him off the bench since that's how he seems to be the most effective -- going up against the other team's starting PG when they're getting tired and/or going against the other team's backup PG who is typically going to have fits dealing with Marcus' defense.
that being said, we don't have a clear option to replace Hayward in the starting line-up at this time if it's not going to be Smart. TT and Teague were not signed to replace Hayward as starters. The young guys are well, young. My best guess for who might start in place of Hayward other than Smart may be GWill depending on what he shows in camp and preseason. He's an intelligent player, adds some beef to the lineup and if he can show he's improved from 3 this year, he could provide a solid 4th option in the starting unit. he won't be that 4th threat to put up over 20 on a given night like we had with Hayward but he could provide solid minutes as a starter. question is who takes his spot off the bench since yet again we don't have a good vet PF we can throw in that spot that can rebound and score.