I'm not totally sure where there's a problem. If you wanted to extrapolate, you could call "a guy or two" (or five) like a micro-small gang, then go to small (15), medium (30), large (60-100), and go one "size" up for each doubling or thereabouts; 150, 300, 600, 1200, 2500, 5000, 10k, 20k, 40k... A fighting force of 5000 with assault rifles would do 1-harm to a force of 10k with 1-armor (3, minus 1 for armor, minus 1 for size), while the 10,000 guys would do 3 (3 minus 1 plus 1).