Here's the mission set our group has been using and tweaking for a few years now:
https://docs.google.com/document/d/1brLLro_8XAutunsTkNYz9BMnfEV41GwNj4alB9WGvGI/edit
Should provide all the detailed rules you'd need to get setup and running with it. Has mission archetypes for ambushes/breakthrough, bunker assaults, retrievals, etc.
One thing we like about this set is that there is always the "primary" objective of the mission which exclusively determines victory. Only in the case of a tie or where the margin of victory is too close to determine a clear winner does the secondary scoring kick in. Secondary scoring is universal: points for securing or breaking into deployment zones, killing the enemy warlord, and
VPs for % of enemy force destroyed.
We want to add an official mechanism for randomly determining some mission "mutators" and how those would apply. Like escalating deployment, weather effects, etc that can randomly kick in or not.