And that is because they can validate incoming tx cos sitting at the tip of the chain with the most PoW being done.
Only as such a valid transaction could be broadcast into the network by a runner.
https://relay.liveinthewoodsfor.win/62efb3baecf3a21f99ac8032b745ddb069508a9a887f260e8cc91c05242d9aae.j...