This is a screenshot I found of OP. Treeline in the makings. All those units plus more not on the picture were linked to the trigger and were acting as the first wave of enemies lunging itself at Gambler. This were taken very early on in the makings of the mission. Ended up deleting all the infantry and adding a lot more vehicles instead for the first wave. All the vehicles were given special scripts I found on a forum somewhere, so that they would keep on driving but the gunner would still engage. Was a big learning experience dealing with the AI in testing of that mission.