You know how in movies you need at least two people to bring their special secret keys, plug them in, and turn them at once to enable a self-destruct sequence? That is a real principle in interface design - if something would be really, really bad to activate unintentionally, make it really, really hard to activate. If you design a nuclear missile facility, you don't put the "launch nukes" button right next to "check…
In my experience, the key is that the UI makes it clear exactly what you're doing. What I mean is, instead of a button that says "Start Imaging", it should be "Start Imaging of the 12,600 computers this rule applies to". Of course, that's a lot more work for the programmer, so it's never done.
It also helps to have sensible conventions for naming hosts and groups. If you need to select a subset of machines then you are sometimes going to make a mistake as simple is getting a wildcard pattern wrong. Instead have groups with explicit and obvious names that require no memory to understand.