Luke, and the Cultural transition of the Gospel

Sir William Ramsay quotes a commentator on Luke as saying he "can be as Hebraistic as the Septuagint and as free from Hebraisms as Plutarch" and that Luke can be Greek when describing Greek society and Hebrew when describing Hebrew society.

Relate those comments with Andrew Walls' theory that the Gospel transitioned cultural mileu at specific times in history. It seems to me that in Luke we are seeing an early example of the transition of the Gospel to Greek culture.

Luke then stands out as unique among the New Testament writers, as someone fully Greek but with a firm understanding of the Hebrew culture.