I get everyone being critical of Luke, he has many errors and makes mistakes in defense, however, he's a damn good runner and that is absolutely vital to every set of six. He's fast and low to the ground and very physical. Skelton also does it well, but he isn't anywhere near as fast and he also has errors in his game.
You just lose so much go forward and running threat in dropping him. Young players make mistakes. I would keep him in the side.
If may is back in not sure who I would drop between Luke and Masi. Tavana has shown enough special ability to lock down the other wing spot. But with tavana on one wing, that makes Luke's hit ups on the other side even more important because he's a much stronger runner.