Generally, I suggest also monitoring Washington County entities. Benton and Washington County police and fire often offer mutual aid and cross county lines in pursuits, etc., especially with I-49 traversing both counties. As mentioned above, it depends on what systems (P25 Phase 2, etc.) your scanner will receive/decode. I don’t often hear other neighboring counties in AR or OK doing much together. But depending on your location, you might hear Madison or Delaware counties.