Mharky, for the majority of orienteers it has nothing to do with being lazy, and more to do with having fun & enjoying the day after a fun weekend. Pushing hard and being towards the front on the first leg of the short open was far more enjoyable for Stodge than running hard for longer and finishing mid-pack without the pressure of being up front and having to get the navigation spot on. He was on an endorphin high for hours after he finished after the buzz of the run

I think it would be more to have every team run the same course and have the class winners from them - first open team, first 120+, first 165+ etc. That would be a fantastic mass start with more opportunity for racing other teams reight down the field. But then either the elite orienteers would be complaining they hadn't been out for long enough, or the older orienteers would be complaining they were out too long...
edit - I hadn't read Mharkys idea before writing this one, but sounds fab to me!