I was taking into consideration what other players were posting as well. Smaller scale, you'd still need a scaling amount of enemies per individual. You have 12 people on a patrol server at once, okay? Each of those 12 people, plus the boss, and 5-15 enemies for each player need to be rendered at once, or else events like this would cause huge fps drops or freezes. That's also probably why the fireteam limit is capped at 6 and only for a specific set of content, in order to keep the game from going lower than the 30 fps threshold. The spider tank is at a much smaller scale than strike bosses and the like, and doesn't even move from Its predefined, maybe 20 feet circle it comes in at.