Neither hart nor KCP is remotely as good as Klay, klay not only has an insane catch and shoot level (the most three pointers made in a season who is not named curry) but also an elite defender who can lockdown any opposite player.
Klay is in different level because he has proven to be a clutch player especially in big games, he is one of the big reason on the success of the Warriors, his outside shooting is really good especially he gets hot.
If lakers could get Klay on their team, it is basically game over. Warriors would be losing Klay in their team and Draymond is getting worse while Cousins will surely not be in the team next year so they will be only left with Curry and Durant whereas Lakers will have Klay and Lebron on their team with a much better roster.
That would good for the NBA organization, their will be a balance of good player and the warriors may loss their starter but they are still the team to bet. Klay and Lebron, that's good, there will be some major adjustment but will certainly lead to a good improvement.
I don't doubt Lakers could beat everyone with Klay on their team not because they will be that much better but because they would also bleed warriors at the same time improving theirs. Of course there are players like JJ Reddick or Buddy Hield who are both amazing three point shooters but since Klay will be still in warriors in that scenario Lakers wouldn't be even close to them.
Just like when we predicted prior to this starts that Lebron will make the Lakers great, but it was not an easy journey, at the start they struggle and currently they are still a mediocre team in the NBA, they haven't proven yet. So, if Klay will land in Lakers, it's still not certain that our expectation will happen.
This season, we have seen how the Lakers struggle without Lebron so they never change, it's like a Cleveland Cavaliers team, Lebron is really a big factor in the team, if it is compared to a pie, he has the biggest portion, maybe like 90%.