Exactly. Now imagine a) is unessarily powerful. I don't want to manage my own list as in b), but other than that, b) sounds fine and c) is also fine, though, does it need an actor in the background? No.

In other words, having a well built concept for these cases is important. At least that's my take. You might say "I'll just use actors and be fine", but for me it's not sufficient.