Note of them are worth the max. At least with Otto Porter you could understand the logic behind it. A player who has improved in every season he has been in the league. He was a borderline all-star in his 4th year. Shot the ball from 3 really well, addressed the position of need for the team, is a very good two way player and was in the age bracket where he could provide "veteranish" leadership but still be young enough to grow with the team.
The 3 guys getting mentioned are not worth the max for varying reasons (not that Porter was but at least you could see the logic). Gordon is an undersized PF who is not a great rebounder or a defender for his position. People hoping he plays the 3 are just living a pipe dream here. His shot has also been hit and miss. Of the 3, he is the one most likely to get the max but it would be such a dumb move, especially for the Kings.
Nurkic would be very good get but then you are getting someone who has historically missed a log of games due to leg injuries. He is a big dude, not particularly mobile so those legs will only get worse as the years go on. Ig you get him, then you need to make sure that your PF is a stud defender. Still not worth the max deal.
Randle has fans within the organization. Coach is a big fan. I can see the attraction there. Solid scorer, solid rebounder, solid passer, doesn't spread the floor all that well and is not a great defender. Not worth the max but someone will be dumb enough to drop it on his probably.
All these guys address 1 or maybe two areas of need but none of them are great fits and none of them address multiple things that Kings need addressing.
Primarily, the Kings need a primary #1 scoring weapon, a tremendous rebounder and a great defender who can anchor the defense. A lot will depend on who the Kings draft. For example, if Kings strike it lucky and get Ayton in the draft then the scoring and the rebounding part is taken care of in a large part. Then the player you want at PF is someone who is a very good defender, rim protector, solid if not better rebounder who can spread the floor. You could get away with someone like Skal in time. Defensively he is a work in progress but there is a shot blocking component and spreading the floor component to his game that is interesting. You could get away with WCS if he caan extend that range on his jumper and be respected for it.