I like Kuzma but this is a big win for the Lakers.
How?
Westbrook is an excellent passer, ball handler, and rebounder. He will take immense pressure off of James and actually allow him to rest a lot more (on the floor). That will give the Lakers a huge advantage at the end of games when James can go full bore and actually have stuff left in the tank. Westbrook will also put relentless pressure on opposing PG's and he gets to the line a lot. I just don't think it is a bad thing for a team to add a guy that plays most every game and is coming off a season averaging 22.2, 11.5 and 11.7. And it isn't like Russ is replacing an elite shooter. Schroder is a better shooter, but isn't a lot better or actually good, and Russ is literally better at everything else (and they still can sign Schroder or sign and trade him). Harrell and KCP are fairly easy to replace role players, and while I like Kuzma, he just isn't a good fit with James and Davis so I think they can replace him fairly easily as well.
Lakers clearly need to add some depth, but I don't think they will have that much difficulty finding some solid role players and they always could still bring back guys like Morris, Matthews, Drummond and Dudley (I expect Caruso and Horton-Tucker to be back).
What is the most they can offer Drummond for a contract? I think it is very hard to win in the NBA without shooting from your stars. Obviously Giannis was not a great shooter, but just about every other player on the team was a good player including middleton as a star. I am surprised you like this deal Mo.
Drummond would have to be the tax payer exception, but I'm honestly not sure he is going to get more than that. KCP is the only good shooter they gave up in the trade. Their next 3 best shooters they can all bring back rather easily (Gasol, Caruso, and McKinnie). McLemore also able to come back rather easily and he was one of their better shooters. The simple reality is the Lakers didn't have much shooting last year and Westbrook doesn't change that at all, but he adds so many dimensions to what they can do that Schroder (or anyone else) can't do.
Now maybe bringing back Schroder and doing the Hield trade might have worked out better, but I suspect the Lakers know they have a really good shot at getting some one to provide some shooting at the 2 guard spot. Like maybe Reggie Bullock.
This seems be a really optimistic read on things. I certainly believe some team would give Drummond more than tax payer exception. He also made it pretty clear that his next contract is important to him and is not in ring chasing part of his career yet. Marc Gasol should retire. He also was upset with his role at points last year so if he did decide to play one final yeah might go back to memphis or something like that. Some of the other guys you mentioned like Dudley and Wes Matthews are not rotation players and really irrelevant.
Now maybe klutch can work some magic and can get some buyouts or guys to take a massive pay cut (like davis west a few years back). I’m just not sure who those players are.
Maybe some team will pay Drummond, maybe not. I think his time at the end in Detroit, and then Cleveland and LA hasn't exactly made him a hot commodity. He is an excellent rebounder, but does like nothing else. Those guys just aren't very valuable.
Gasol certainly could retire, but he is under contract with the Lakers, so he isn't going anywhere else in the NBA without the Lakers blessing. I think his issues were losing time to Drummond and frankly he was probably right. Gasol provides a needed element for the Lakers with his shooting. They'd love to have him back for 15-20 mpg to provide some spacing, passing, shooting, etc.
Matthews played 20 mpg or so for the Lakers last year and started 10 games for them. He played like 18 mpg in the playoffs. He is absolutely a rotation player still (not a starter, but a solid 7th/8th man type player). I agree on Dudley, if he has anything at all left, it is basically nil.
But this is LA and the Lakers. They will find players because of that fact alone, but also because they are clearly a title contender and players often want to do the ring chasing thing (and again it is LA).
I have no idea if Westbrook will work with James/Davis, but I think he will work better than Schroder did as he is a significantly better player than Schroder and does everything Schroder does better than him, except shoot, but Schroder isn't a good shooter so I'm not sure that is anything more than a negligible loss (Schroder is better shooter than Westbrook, just not good). They obviously have to fill in their depth, but they have a top 3 player in James, a top 10 player in Davis, and a top 20 (or so) player in Westbrook. That is a very good starting point for a title contender. They just need to stay healthy and get some bodies in there. And given their contender status and the fact that they are the Lakers in LA, I just don't think it will be hard for them to find the bodies.