The section mentioned in my subject doesn't make sense to me, is anyone able to clarify? As all collections must have a limiting collection and "all systems" is the only built in collection for devices, any collection you create must be limited to "all systems" whether directly or indirectly so if the data is inaccurate at that point, all collection data will be inaccurate.
If this is not correct, give an example of a collection that you would not limit to All systems at some point. Even if you create a collection to limit all future collections to, this initial collection must be limited to "All Systems" which as stated may not contain valid client information meaning all collections will contain invalid information.
EDIT - my statement that "all systems" was the only built in collection was incorrect, "All Desktop and Server Clients" is also built in, so I have restricted most collections to this. The only issue there is that any machine that doesn't show as having a client is now no longer included in any collection. Fine for deployment collections, however where we had collections used for maintenance as in identifying pingable machines that had broken clients etc, I have had to create an "all devices without a client" limited to All Systems to use as a limiting collection for any of these type of collections. It means the insight will never be clear, but at least there will only be one collection showing now.