Schmebulock's consensus

The strength of gnomes lies in their coordinated action. Being small and subtle creatures themselves, the forest gnomes can form large swarms acting as one giant creature. This unusual defense strategy required a lot of skill and training as directing a swarm is not an easy task! Initially, gnomes used leader-based control algorithms, although those have proven to be vulnerable to abuse and failure. After thorough research and study, gnomes developed their own leaderless consensus algorithm based on very simple rules. It is based on local broadcast (gossip) in an open network of a known radius $r$. One of the gnomes proposes a plan which then spreads gnome to gnome. If there is agreement, all gnomes act \emph{all at once}. If there are conflicting plans (an extreme rarity), they try again. The resulting swarm reaction time is exactly the swarm round-trip time $2rt$, where $t$ is the command relay time. The algorithm is non-Byzantine; all gnomes must be sane and sober.