I’m sorry but that’s just not true, at least about Yoda, season one episode one, Yoda has the clone troopers he is with take off their helmets, and he points out each of their unique abilities and traits. He said something along the lines of each of you are unique in the force, that isn’t a direct quote, but it’s a summary. That doesn’t sound like a person who thinks that they are expendable, that sounds like someone who cares. Despite his many flaws, I do think that Yoda cared. Droids have no signature in the force, they are just metal, but clones are human, the force surrounds and binds them together too, and Yoda knew that.