-New map (original problem on Altis, this instance on Stratis)
-Place player
-Place Rifle Squad (I am only placing one in this instance)
-Place High Command - Commander
-Place High Command - Subordinate
-Ungroup High Command modules from each other
-Sync the Player to High Command - Commander, High Command - Commander to High Command - Subordinate, High Command - Subordinate to Rifle Squad Leader
-Place a Tank Platoon
-Place a Trigger on the other end of the Airbase
-Under the trigger select OPFOR as the faction
-Under the trigger select 'Not Present'
-Under the trigger add code (not in quotes) to onAct "Player hcSetGroup [tank]"
-Assign the player the Name: Player
-Assign the lead tank in the tank platoon the Name: tank
-Click Preview and look at High Command bar with only the rifle squad, no tank platoon

My original problem was on Altis in the salt flats trying to test some concepts for a map I want to make. The reproduction was at the Airbase on stratis. Both yielded the exact same results. I believe I am following the syntax from the BI page (https://community.bistudio.com/wiki/hcSetGroup).