God and Father is the ultimate saviour.
This is good, and it is pleasing in the sight of God our Saviour 1 Tim 2:3
He has prepared the plan, which included Jesus to be the Lamb, hence saviour.
God, who needed a perfect sacrifice for sin, could not save without the Lamb, the logos become flesh. Jesus could not be saviour without his God helping him get to the cross without sin Heb 5:7.
or our citizenship is in heaven, from which we also eagerly wait for a SaviorSaviour, the Lord Jesus Christ Phil 3:20
There was mention of a ‘rescue boat’. Indeed, Jesus may be that boat, in which all are saved, but God was steering the boat. He built the boat, commissioned the boat, and took great delight in its maiden voyage!
Therefore let all the house of Israel know for certain that God has made Him both Lord and Christ-this Jesus whom you crucified Acts 2:36
Jesus is the Lamb, the Messiah, the Prince of Peace, Root of David and many other glorious names and titles. He is also Saviour. A name God is also called - but God is never called Messiah, the Lamb, the Root of David etc.
So they share the role of Saviour in quite different ways. God has the responsibility of having a plan of salvation. Jesus has the role of being the fulfilment of that plan which was in place before the world began - as Saviour in God's service and for all mankind.
They cannot do each other's role of Saviour. God cannot die or be tempted, Jesus cannot orchestrate the details of salvation - but he has a vital role that no one else could do.