One thing I've admired about OWR over the years is their consistency. I remember OWR launching, and they have remained persistent throughout the years. Many of the upstarts over that period, mine included, dwindled. They didn't.
A significant contributor to a successful alliance is developing that core, foundational group of members that value the relationships established with one another more than any extraneous event that could potentially derail a micro. Usually, a micro will fail ultimately from within, but the spark to that failure could be something like Arrgh raiding you. Having assembled that core membership, though, will enhance your ability to withstand those and other disruptions.