The Toiyabe National Forest in western Nevada and eastern California will transmit a dispatch on the Toiyabe NF Forest Net and the BLM Carson City District at the same time. If any units to be dispatched are not in the coverage of the repeater used to make the initial dispatch then additional repeaters will be keyed up one at a time to make sure all units have received the dispatch.
Other National Forests that are large and topography is such that one repeater cannot be heard over most of the forest, at least by all of the stations (ranger and fire), then dispatches will be repeated on other repeaters depending on the units included on the dispatch. Morning and afternoon weather works in the same way. National Forests that are spread out, such as the Cibola in New Mexico and the Coronado in Arizona have this multiple transmission procedure. When I was on the Cibola NF in the late 70's the local remote base for the Magdalena Ranger District was used to broadcast the weather, but not everyone in the field could hear this remote as there were areas that could not hear the forest net unless it was transmitted on a repeater. All the stations on the district could hear the remote, but people in the field on the back side of a mountain range, in this case the San Mateo Mountains could not receive or transmit to the remote base located at the top of the Magdalena Mountains. The comm center could not possibly transmit the weather and other forest wide announcements over every repeater.
People in the field that missed the weather and needed it requested it be transmitted on the repeater they were using. Dispatchers also kept track of where units were and if a forest wide announcement was made the dispatcher would call individuals on the corresponding repeater to make sure that person heard the announcement.if it was time sensitive. The initiation of fire restrictions is an example of a time sensitive announcement that everyone in the field needed to hear. The Inyo National Forest, which I retired from and now live near, is over 160 miles long from north to south. Announcements are transmitted simultaneously on the north and south nets on the repeater that covers the most terrain in those areas. Some large areas of the forest are not covered by these two repeaters so the situation is similar to the Cibola's.
I hope this answers your questions zerg.