On all state systems, there are certain sites that have access locked to specific users only, or block out certian users. Like an site that is specific to MDOC, if you sit on it and run Pro96Com etc., I am willing to bet you won't see much other traffic allowed except MDOC. I would also bet that on the certain Hinds County sites, you don't get much out of County allowances beyond a certain point. There is usually an "area" of allowed users around a site for interop, but use by everyone is usually not allowed, or only allowed by permission, or on certain TG's only. There are issues if "dragging" TG's systemwide is allowed. Sites can be overloaded when that happens. They found this out on AWIN, and now regularly send out reminders to all users that "dragging" TG's is not proper use of the network. This is why there are regional event/interop TG's if needed, and its just plain rude to want to monitor your Laurel PD Dispatch TG when your on a trip to say Greenwood to go fishing. This is also where the combination of FirstNet in with the MSWIN would be good, and those that use the APX NEXT, or similar radios can switch to the LTE side to talk with users anywhere without clogging up multiple LMR sites.
Then you could be visiting granny over in Natchez, and talk to Lt. Dan in Petal and only have the Forrest County site running the TG. Or even be sitting with me in Indy having a tenderloin sammie, and talk to Cap'n Crunch in H'burg etc...