How do Trinitarians explain Titus 1:3 & 4 in light of Isaiah 43:11?

There is a question asking how non-trinitarians explain Isaiah 43:11, but this one seeks trinitarian explanation as connected to other verses in Titus. > “Before me there was no God formed, neither shall there be after me. > 11 I, even I, am the Lord; and ***beside me there is no saviour***.” > Isaiah 43:11 A.V. [Emphasis mine] > > “…according to the commandment of ***God our Saviour***… Grace, mercy and > peace, from God the Father and the Lord Jesus ***Christ our Saviour***.” > Titus 1:3 & 4 A.V. [Emphasis mine] The query is, **who has the divine role of being Saviour? In Isaiah it is Yahweh, and only him. In Titus it is both God and Jesus Christ.** It appears that there cannot be two Saviours (according to Isaiah). So, why does Titus say what it says? (Both God and Jesus Christ are – again – designated ‘Saviour’ in Titus 2:13 & 3:4 – repetition for emphasis; so, in this letter to Titus there has not been a scribal error. Both sets of statements in Titus agree.) However, the question is not a hermeneutic one regarding Greek language in Titus; it is about ***how the claims in Titus can stand in view of Isaiah 43:11 categorically stating that only God is Saviour.*** How do Trinitarians explain this?