John 10 is the foundation because Jesus tells us specifically who He died for, and other scripture should not contradict it. If you go beyond what Jesus specifically said regarding who He died for, you are in assumption. Jesus Christ is the Chief Stone and true preachers build upon that 1 Cor 3 11John 10 is not the totality of the record
If you read Paul alone when he stated Christ gave himself for me would you conclude he died for Paul alone ?
Your methodology is faulty
Because you do not consider the totality of scripture
and you do this time and time again
For other foundation can no man lay than that is laid, which is Jesus Christ.