There’s always the add more of everything so something could fail without impacting the stability aspect, and that’s great for a corporation needing the redundancy; but it’s probably prudent to not forget there’s also the “I’m interested in learning” aspect, where people running a home server to play with software side of things.
You’re spot on in that we’d need to know what it is that OP would like to do with the system, but I’m getting the feeling that stability isn’t that high of a concern just yet.