appearance rate was a bit too rough id say, people shouldnt be grinding on the maps for hours on end to have an opportunity to skip the event poke. The idea of the event poke being rarer than leg is pretty good but this was too rare to justify it.
luck definately factors into how many you will encounter, but when the base rate itself is so low, the chances of luck being on your side are slim to none :p. Patricks a smert guy, i think he will make improvements as im also positive this event was to test "finding pokes on map" kind of events.