Just saying that ANY playoff contender in the west with a better defense than the Lakers will have a distinct advantage over the Lakers, in a playoff series. Right of the top of my head, OKC, Minn, and Denver all pop of the top of my head as distinctly better defensive teams. Nothing to do this year, since whatever gains you get from Luka, you lose because of Davis who STILL is a top 3 big man who scores rebounds and defends at top level. The Lakers will first have to get an immediate legit big man, and even Polenka said that there aren't any out there this coming off season. And developing big men from scratch takes 3-4 years if you are lucky to hit on one.
Labron will reach the point where even HIS remarkable body will start to take its toll. Christ he'll be in his 41-42nd year. Don't tell me you haven't noticed the slippage in Al's 39th year. Time is undefeated and it's coming for Labron SWIFTLY
Now go back further to 5 years down the road and assuming he is healthy and still interested, the advantage shifts to the Lakers as Luka gets into his late 20's and early 30's and Davis exits the stage, but we live in a recency bias world. We aren't going to be patient waiting for the Pats to grow over time, neither are Lakers fans going to want to wait 5 years to see another championship arrive.
AND btw, there is no guarantee that Luka even sign with LA after next season. He will be free to sign for the Max with ANYONE next year and a completely unrestricted FA (as I hear it). Something he can't do now