7 actors gone after season 4 cast cuts
Apparently the budget was significantly cut for season 4. The only ones remaining are the Kents, their sons and the guy playing Luther who's been bumped up to series regular. I'll miss Dylan Walsh. The rest became dead weight that bogged the show down in sappy melodrama. Maybe now they can concentrate on the superman stuff and not the soapy, who's sleeping with who, dramas of Smallville.
https://www.tvinsider.com/1096288/superman-lois-dylan-walsh-emmanuelle-chriqui-cast-budget-cuts/