Hi and greetings from the Philippines. We share the same woes on some host teams here who advertise their games as "milsim" but is actually speedball with a little twist of some mission thingy like going after a car battery in the middle that is supposed to be a bomb diffuser thing. We get a lot of that here. But fortunately there are those of us who are loyal to milsim. To get to the point. Sometimes the areas we setup milsim may not be that big enough to host big contingents. And if there are big enough spaces, they're usually inhabited by rebels who don't carry airsoft guns. So we improvised.
Our concept is special ops type of milsim gameplay that involves intel gathering, cqb (in an actual building) and land navigation (using grid maps) in small areas to locate certain op's or camps. So instead of one platoon or company against another, we pit small groups of between 8-12 man teams (squad size really) against a dedicated opfor who role plays and follows a script. And there are multiple short missions that last no more than 30-45 minutes per team. We score it based on missions accomplished less hit players over time. So far it's been a good enough formula for us.