If the missile is MIRVed it could max it out.Not Individually.Discrimination algorithms enable defense systems to compare objects in a target scene to determine which to intercept. SM-3 has flown and demonstrated fundamental discrimination capability for unitary threats.
MIRVing doesn’t happen until somewhere at the top of the trajectory... that’s why they’re called independent re-entry vehicles. If Aegis caught one before it MIRVed, it would obviously prevent the MIRVing.