Per the Athletic Fox / Hield / Barnes / Bagley / Holmes was at one point the 6th-best lineup in the NBA with +10 pts per 100 possessions. That was like 2 weeks ago but if we’re talking bags vs Holmes that’s worth pointing out
It's now 3rd best, if you sort by lineups with over 75 minutes played:
https://go.nba.com/q7lq (I'm not sure if that's a reasonable filter or not, but it's what bleacher report used in the article Carmichael Dave recently highlighted on Twitter).
Just looking at the Kings, I moved the filter down to 14 minutes or more, and it shows the top-10 most used lineups, sorted by net rating:
https://go.nba.com/vmqx Many of these aren't used that frequently at all, though, so I'm not sure whether we can trust the sample size yet. With the starters v. finishers argument, though, I think you can, and I think the evidence backs up Luke's end of game rotation for now.