The so-called New Perspective on Paul isn’t really new. Peter Leithart sees the ‘New Perspective’ in Augustine’s reading of Galatians, and Michael Bird even finds both Old and New perspectives in the Epistle to Diognetus. The two soteriological views, at least to the writer of the Epistle to Diognetus, aren’t mutually exclusive.
A prolepsis, maybe, of a synthesis to come.
He therefore that ministereth to you the Spirit, and worketh miracles among you, doeth he it by the works of the law, or by the hearing of faith? Even as Abraham believed God, and it was accounted to him for righteousness. Know ye therefore that they which are of faith, the same are the children of Abraham. […] There is neither Jew nor Greek, there is neither bond nor free, there is neither male nor female: for ye are all one in Christ Jesus.