The Lakers would become legitimate title contenders right away
This trade would make a lot of sense for the Lakers. Turner is the best player in this hypothetical trade and would help the Lakers become a winning team again immediately. Additionally, adding him to the team would give the Lakers arguably the best frontcourt in the league, pairing him alongside James and Davis.
What would make Turner an interesting addition to the Lakers is his versatility on both sides of the ball. He is one of the best shooting big men in the NBA, which would do wonders for the Lakers' offense. Furthermore, he is a good defender who could complement Davis very well.
By adding Turner, this would also allow the Lakers to move Davis back to his natural power forward position, which is something the team reportedly had interest in doing earlier this offseason.
Additionally, acquiring Mathurin could be good for the Lakers. In his two seasons with the Pacers, the 22-year-old has played well, averaging 15.8 points on 43.9% shooting from the floor. Initially, he would likely assume the role of the Lakers' sixth man, but he could help the team a lot as a starter and core player in the long run, especially after James retires.