Their pets fire at whatever gets nearby, not only minions. And please don't characterize this as "how MMs play" in the first place, because you're suggesting every person who plays an MM plays this way (not true), and it's also not a related topic.
Now listen: one of the leeches that I kept reporting would often have what I would assume were alt account characters (they were all members of the same SG, all) parked up in the AE building; usually four of them. My guess is they were on the team with the MM down in the parking lot (who wasn't in league), and were leveling up and catching drops without doing a single thing, while the MM below let his pets do the work. Meanwhile, I was down there clicking doors and targeting mobs, rezzing others and serving as anchor - even with one of my MMs. Now tell me who was doing real work and who was leeching. Exploits are expressly disallowed in the rules.
But hey, once again, let me extend an invite, please invite me the next time you play, so that I can tag along behind you to demonstrate what I'm talking about. 😃