I would very much doubt Algeria is buying 6 in total. But 2 to 3 seems plausible given how many Chinese warships they have ordered in the past.12 052DE would immediately put any country ahead of Russia, UK and France in terms of destroyer firepower.
Shilao and Yankee said they could entertain that the Algerian news was real (buy 3, technology transfer then self assemble 3 more), but not Saudi buying 12. The fact that this rumour about Saudi buying 12 emerging makes them doubt the Algeria news too now.
As for the Saudis, they bought LCS. Com'on, even they must know it's garbage. US Navy is not even hiding how little they think of it. So it would not surprise me if they bought 2 or 3 of them. Whether or not they need 7000t surface ships is a different story.