They are doing pitched battle scenarios. The three scenarios are all objective based (1, 2, and 4) from the General's Handbook. So major/minor victories are based on that. Tie breakers are decided point values of units that are completely wiped. So if you start with a block of 20 skeletons and you end with just one model remaining, your opponent gets zero points for that unit, even if they killed more than 20 models from the unit.
I know that people debate about this, but I think nearly ever faction has a way to restore wounds/models and this was the fairest way to do it.
I'm even giving up a command ability by taking the ghoul king and maxing out my points, which puts me at a slight disadvantage, but I think it's worth it.