No serious race walk event should have any 5k part though. That is just way too short and completely kills the whole point of the sport, it leads to things like Tom Bosworth's running 1 mile to set the 1 mile 'race walking' record. Actually, 20km is already too short, but alright. It'd be better to remove race walking altogether than to go for events where a single athlete does less than 20km in one race.
One of the main reasons why 50k was so awesome is because race walking, more than anything, is about endurance, endurance, endurance.